Linux Cubed Series 7: Sunsite/Linux Cubed Series 7 - Sunsite Vol 1.iso/system/mail/delivery/sendmail.002/sendmail/sendmail-8.7.3-bin/sendmail-operation-manual.doc

Text File | 1995-10-21 | 265.4 KB | 7,261 lines

                          SSEENNDDMMAAIILL

              IINNSSTTAALLLLAATTIIOONN AANNDD OOPPEERRAATTIIOONN GGUUIIDDEE

                        Eric Allman
             University of California, Berkeley
                      Mammoth Project
                    [e-mail]

                        Version 8.67

                  For Sendmail Version 8.7




     _S_e_n_d_m_a_i_l implements a general purpose internetwork mail
routing facility under the UNIX(R) operating system.  It  is
not  tied  to any one transport protocol -- its function may
be likened to a crossbar switch, relaying messages from  one
domain  into  another.   In the process, it can do a limited
amount of message header editing to put the message  into  a
format that is appropriate for the receiving domain.  All of
this is done under the control of a configuration file.

     Due to the requirements of  flexibility  for  _s_e_n_d_m_a_i_l,
the  configuration  file  can  seem somewhat unapproachable.
However, there are only a few basic configurations for  most
sites, for which standard configuration files have been sup-
plied.  Most other configurations can be built by  adjusting
an existing configuration files incrementally.

     _S_e_n_d_m_a_i_l is based on RFC821 (Simple Mail Transport Pro-
tocol), RFC822  (Internet  Mail  Format  Protocol),  RFC1123
(Internet  Host Requirements), RFC1521 (MIME), RFC1651 (SMTP
Service Extensions), and a series of as-yet-draft  standards
describing  Delivery  Status Notifications (DSNs), available
from the internet drafts  sites  as  draft-ietf-notary-mime-
delivery-_X_X.txt,       draft-ietf-notary-mime-report-_X_X.txt,
draft-ietf-notary-smtp-drpt-_X_X.txt,  and  draft-ietf-notary-
status-_X_X.txt (replace _X_X by the latest draft number).  How-
ever, since _s_e_n_d_m_a_i_l is designed to work in a  wider  world,
in  many  cases  it can be configured to exceed these proto-
cols.  These cases are described herein.

     Although _s_e_n_d_m_a_i_l is intended to run without  the  need
for monitoring, it has a number of features that may be used
to monitor or adjust the  operation  under  unusual  circum-
stances.  These features are described.


SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee           SSMMMM::0088--11







SSMMMM::0088--22           SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


     Section  one  describes  how  to  do  a  basic _s_e_n_d_m_a_i_l
installation.  Section two explains the day-to-day  informa-
tion  you  should know to maintain your mail system.  If you
have a relatively normal site,  these  two  sections  should
contain  sufficient  information for you to install _s_e_n_d_m_a_i_l
and keep it happy.  Section three describes some  parameters
that  may  be  safely tweaked.  Section four has information
regarding the command line arguments.  Section five contains
the  nitty-gritty  information about the configuration file.
This section is for masochists and  people  who  must  write
their own configuration file.  Section six describes config-
uration that can be done at  compile  time.   Section  seven
gives  a brief description of differences in this version of
_s_e_n_d_m_a_i_l.  The appendixes give a brief but detailed explana-
tion  of  a  number of features not described in the rest of
the paper.

     WWAARRNNIINNGG:: Several major changes were introduced in  ver-
sion  8.7.   You should not attempt to use this document for
prior versions of _s_e_n_d_m_a_i_l.











































SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee           SSMMMM::0088--77


11..  BBAASSIICC IINNSSTTAALLLLAATTIIOONN

        There are two basic steps  to  installing  _s_e_n_d_m_a_i_l.
   The  hard part is to build the configuration table.  This
   is a file that _s_e_n_d_m_a_i_l reads  when  it  starts  up  that
   describes  the  mailers  it  knows  about,  how  to parse
   addresses, how to rewrite the  message  header,  and  the
   settings  of various options.  Although the configuration
   table is quite complex, a configuration  can  usually  be
   built  by  adjusting an existing off-the-shelf configura-
   tion.  The second part is actually  doing  the  installa-
   tion, i.e., creating the necessary files, etc.

        The  remainder  of  this  section  will describe the
   installation of _s_e_n_d_m_a_i_l assuming you can use one of  the
   existing  configurations  and that the standard installa-
   tion parameters are acceptable.  All pathnames and  exam-
   ples  are  given  from  the root of the _s_e_n_d_m_a_i_l subtree,
   normally _/_u_s_r_/_s_r_c_/_u_s_r_._s_b_i_n_/_s_e_n_d_m_a_i_l on 4.4BSD.

        If you are loading this off the tape, continue  with
   the  next  section.  If you have a running binary already
   on your system, you should probably skip to section  1.2.

   11..11..  CCoommppiilliinngg SSeennddmmaaiill

           All  _s_e_n_d_m_a_i_l  source is in the _s_r_c subdirectory.
      If you are running on a 4.4BSD system, compile by typ-
      ing  "make".   On  other systems, you may have to make
      some other adjustments.  On most systems, you  can  do
      the appropriate compilation by typing

          sh makesendmail

      This  will  leave the binary in an appropriately named
      subdirectory.  It works for multiple  object  versions
      compiled out of the same directory.

      11..11..11..  TTwweeaakkiinngg tthhee MMaakkeeffiillee

              _S_e_n_d_m_a_i_l  supports  two  different formats for
         the local (on disk) version of  databases,  notably
         the _a_l_i_a_s_e_s database.  At least one of these should
         be defined if at all possible.

         NDBM      The  ``new  DBM''  format,  available  on
                   nearly  all  systems  around today.  This
                   was the preferred format prior to 4.4BSD.
                   It allows such complex things as multiple
                   databases and closing  a  currently  open
                   database.












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         NEWDB     The  new  database package from Berkeley.
                   If you have this, use it.  It allows long
                   records,  multiple  open  databases, real
                   in-memory caching, and so forth.  You can
                   define  this  in  conjunction with one of
                   the other two; if you do,  old  databases
                   are read, but when a new database is cre-
                   ated it will be in NEWDB  format.   As  a
                   nasty  hack, if you have NEWDB, NDBM, and
                   NIS defined, and if the alias  file  name
                   includes  the  substring "/yp/", _s_e_n_d_m_a_i_l
                   will create both new and old versions  of
                   the alias file during a _n_e_w_a_l_i_a_s command.
                   This is required because the  Sun  NIS/YP
                   system reads the DBM version of the alias
                   file.  It's ugly as sin, but it works.

         If neither of these are defined, _s_e_n_d_m_a_i_l reads the
         alias  file  into memory on every invocation.  This
         can be slow and should be avoided.  There are  also
         several methods for remote database access:

         NIS       Sun's  Network Information Services (for-
                   merly YP).

         NISPLUS   Sun's NIS+ services.

         NETINFO   NeXT's NetInfo service.

         HESIOD    Hesiod service (from Athena).

         Other compilation  flags  are  set  in  conf.h  and
         should be predefined for you unless you are porting
         to a new environment.

      11..11..22..  CCoommppiillaattiioonn aanndd iinnssttaallllaattiioonn

              After making the  local  system  configuration
         described  above, You should be able to compile and
         install the system.  The script  "makesendmail"  is
         the best approach on most systems:

             sh makesendmail

         This  will use _u_n_a_m_e(1) to select the correct Make-
         file for your environment.

              You may be able to install using

             sh makesendmail install

         This should install the  binary  in  /usr/sbin  and
         create    links    from   /usr/bin/newaliases   and










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee           SSMMMM::0088--99


         /usr/bin/mailq to  /usr/sbin/sendmail.   On  4.4BSD
         systems  it will also format and install man pages.

   11..22..  CCoonnffiigguurraattiioonn FFiilleess

           _S_e_n_d_m_a_i_l cannot operate without  a  configuration
      file.   The  configuration  defines  the mail delivery
      mechanisms understood at  this  site,  how  to  access
      them, how to forward email to remote mail systems, and
      a number of  tuning  parameters.   This  configuration
      file  is  detailed  in the later portion of this docu-
      ment.

           The _s_e_n_d_m_a_i_l configuration  can  be  daunting  at
      first.   The world is complex, and the mail configura-
      tion reflects  that.   The  distribution  includes  an
      m4-based configuration package that hides a lot of the
      complexity.

           These configuration files are  simpler  than  old
      versions largely because the world has become simpler;
      in particular, text-based host  files  are  officially
      eliminated,  obviating the need to "hide" hosts behind
      a registered internet gateway.

           These files also assume that most of your  neigh-
      bors   use  domain-based  UUCP  addressing;  that  is,
      instead of naming hosts as "host!user" they  will  use
      "host.domain!user".   The  configuration  files can be
      customized to work around this, but it  is  more  com-
      plex.

           Our  configuration  files  are processed by _m_4 to
      facilitate local customization; the  directory  _c_f  of
      the   _s_e_n_d_m_a_i_l  distribution  directory  contains  the
      source files.  This directory contains several  subdi-
      rectories:

      cf        Both   site-dependent  and  site-independent
                descriptions of hosts.  These can be literal
                host  names  (e.g.,  "ucbvax.mc")  when  the
                hosts are gateways or more general  descrip-
                tions  (such  as  "tcpproto.mc" as a general
                description of  an  SMTP-connected  host  or
                "uucpproto.mc" as a general description of a
                UUCP-connected  host).   Files  ending   ..mmcc
                (``Master  Configuration'')  are  the  input
                descriptions; the output is  in  the  corre-
                sponding ..ccff file.  The general structure of
                these files is described below.

      domain    Site-dependent    subdomain    descriptions.
                These  are tied to the way your organization










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                wants  to  do  addressing.    For   example,
                ddoommaaiinn//ccss..eexxppoosseedd..mm44  is our description for
                hosts in the CS.Berkeley.EDU subdomain  that
                want  their individual hostname to be exter-
                nally visible;  ddoommaaiinn//ccss..hhiiddddeenn..mm44  is  the
                same  except  that  the  hostname  is hidden
                (everything  looks  like   it   comes   from
                CS.Berkeley.EDU).    These   are  referenced
                using the DOMAIN mm44 macro in the ..mmcc file.

      feature   Definitions of specific features  that  some
                particular  host  in  your  site might want.
                These are referenced using  the  FEATURE  mm44
                macro.   An  example  feature is use_cw_file
                (which   tells   _s_e_n_d_m_a_i_l   to    read    an
                /etc/sendmail.cw file on startup to find the
                set of local names).

      hack      Local hacks, referenced using  the  HACK  mm44
                macro.   Try  to  avoid these.  The point of
                having them here is to make  it  clear  that
                they smell.

      m4        Site-independent  _m_4(1)  include  files that
                have information common to all configuration
                files.    This   can  be  thought  of  as  a
                "#include" directory.

      mailer    Definitions of mailers, referenced using the
                MAILER  mm44 macro.  The mailer types that are
                known in this distribution are  fax,  local,
                smtp,  uucp,  and  usenet.   For example, to
                include support for the UUCP-based  mailers,
                use "MAILER(uucp)".

      ostype    Definitions   describing  various  operating
                system environments (such as the location of
                support  files).  These are referenced using
                the OSTYPE mm44 macro.

      sh        Shell files used by the  mm44  build  process.
                You shouldn't have to mess with these.

      siteconfig
                Local  site  configuration information, such
                as UUCP connectivity.  They normally contain
                lists of site information, for example:

                    SITE(contessa)
                    SITE(hoptoad)
                    SITE(nkainc)
                    SITE(well)











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                They  are  referenced  using  the SITECONFIG
                macro:

                    SITECONFIG(site.config.file, name_of_site, X)

                where _X is the macro/class name to use.   It
                can   be  U  (indicating  locally  connected
                hosts) or one of W, X, or Y for up to  three
                remote UUCP hubs.

           If you are in a new domain (e.g., a company), you
      will probably want to create a cf/domain file for your
      domain.  This consists primarily of relay definitions:
      for  example,  Berkeley's  domain  definition  defines
      relays  for  BitNET,  CSNET, and UUCP.  Of these, only
      the UUCP relay is particularly specific  to  Berkeley.
      All  of these are internet-style domain names.  Please
      check to make certain they  are  reasonable  for  your
      domain.

           Subdomains  at  Berkeley  are also represented in
      the cf/domain directory.  For example, the domain  cs-
      exposed  is  the  Computer  Science subdomain with the
      local hostname shown to other users;  cs-hidden  makes
      users  appear to be from the CS.Berkeley.EDU subdomain
      (with no local host information included).   You  will
      probably have to update this directory to be appropri-
      ate for your domain.

           You will have to use or create ..mmcc files  in  the
      _c_f_/_c_f  subdirectory  for your hosts.  This is detailed
      in the cf/README file.

   11..33..  DDeettaaiillss ooff IInnssttaallllaattiioonn FFiilleess

           This subsection describes the files that comprise
      the _s_e_n_d_m_a_i_l installation.

      11..33..11..  //uussrr//ssbbiinn//sseennddmmaaiill

              The   binary   for   _s_e_n_d_m_a_i_l  is  located  in
         /usr/sbin1.  It should be setuid root.   For  secu-
         rity  reasons,  /,  /usr,  and  /usr/sbin should be
         owned by root, mode 7552.
____________________
   1This is usually /usr/sbin on 4.4BSD and  newer  systems;
many  systems install it in /usr/lib.  I understand it is in
/usr/ucblib on System V Release 4.
   2Some vendors ship them owned by bin; this creates a  se-
curity hole that is not actually related to _s_e_n_d_m_a_i_l.  Other
important directories that should  have  restrictive  owner-
ships  and  permissions  are /bin, /usr/bin, /etc, /usr/etc,
/lib, and /usr/lib.










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      11..33..22..  //eettcc//sseennddmmaaiill..ccff

              This is the configuration file for  _s_e_n_d_m_a_i_l3.
         This and /etc/sendmail.pid are the only non-library
         file names compiled into _s_e_n_d_m_a_i_l4.

              The configuration  file  is  normally  created
         using  the  distribution files described above.  If
         you have a particularly unusual  system  configura-
         tion you may need to create a special version.  The
         format of this file is detailed in  later  sections
         of this document.

      11..33..33..  //uussrr//bbiinn//nneewwaalliiaasseess

              The  _n_e_w_a_l_i_a_s_e_s  command should just be a link
         to _s_e_n_d_m_a_i_l:

             rm -f /usr/bin/newaliases
             ln -s /usr/sbin/sendmail /usr/bin/newaliases

         This can be installed in whatever search  path  you
         prefer for your system.

      11..33..44..  //vvaarr//ssppooooll//mmqquueeuuee

              The directory _/_v_a_r_/_s_p_o_o_l_/_m_q_u_e_u_e should be cre-
         ated to hold the mail queue.  This directory should
         be mode 700 and owned by root.

              The  actual  path of this directory is defined
         in the QQ option of the _s_e_n_d_m_a_i_l_._c_f file.

      11..33..55..  //eettcc//aalliiaasseess**

              The system aliases are held in "/etc/aliases".
         A  sample  is given in "lib/aliases" which includes
         some aliases which _m_u_s_t be defined:

             cp lib/aliases /etc/aliases
             _e_d_i_t _/_e_t_c_/_a_l_i_a_s_e_s

____________________
   3Actually, the pathname varies depending on the operating
system; /etc is the preferred directory.  Some older systems
install it in //uussrr//lliibb//sseennddmmaaiill..ccff, and I've also seen it in
//uussrr//uuccbblliibb and //eettcc//mmaaiill.  If you want to move  this  file,
change _s_r_c_/_c_o_n_f_._h.
   4The system libraries can reference other files; in  par-
ticular,  system  library  subroutines  that  _s_e_n_d_m_a_i_l calls
probably reference _/_e_t_c_/_p_a_s_s_w_d and _/_e_t_c_/_r_e_s_o_l_v_._c_o_n_f.












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         You should extend this file with any  aliases  that
         are apropos to your system.

              Normally  _s_e_n_d_m_a_i_l looks at a version of these
         files maintained by the _d_b_m(3) or  _d_b(3)  routines.
         These  are  stored either in "/etc/aliases.dir" and
         "/etc/aliases.pag" or  "/etc/aliases.db"  depending
         on which database package you are using.  These can
         initially be created as empty files, but they  will
         have  to  be initialized promptly.  These should be
         mode 644:

             cp /dev/null /etc/aliases.dir
             cp /dev/null /etc/aliases.pag
             chmod 644 /etc/aliases.*
             newaliases

         The _d_b routines preset the mode reasonably, so this
         step  can be skipped.  The actual path of this file
         is defined in the AA option of the _s_e_n_d_m_a_i_l_._c_f file.

      11..33..66..  //eettcc//rrcc

              It  will be necessary to start up the _s_e_n_d_m_a_i_l
         daemon when your system reboots.  This daemon  per-
         forms  two functions: it listens on the SMTP socket
         for connections (to receive mail from a remote sys-
         tem)  and  it  processes  the queue periodically to
         insure that mail gets delivered when hosts come up.

              Add  the  following  lines  to  "/etc/rc"  (or
         "/etc/rc.local" as appropriate) in the  area  where
         it is starting up the daemons:

             if [ -f /usr/sbin/sendmail -a -f /etc/sendmail.cf ]; then
                  (cd /var/spool/mqueue; rm -f [lnx]f*)
                  /usr/sbin/sendmail -bd -q30m &
                  echo -n ' sendmail' >/dev/console
             fi

         The  "cd"  and  "rm"  commands insure that all lock
         files have been removed; extraneous lock files  may
         be  left around if the system goes down in the mid-
         dle of processing a message.  The line  that  actu-
         ally  invokes  _s_e_n_d_m_a_i_l has two flags: "-bd" causes
         it to listen on the SMTP port, and  "-q30m"  causes
         it to run the queue every half hour.

              Some people use a more complex startup script,
         removing zero length qf  files  and  df  files  for
         which there is no qf file.  For example, see Figure
         1 for an example of a complex startup script.











SSMMMM::0088--1144          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee



____________________________________________________________

# remove zero length qf files
for qffile in qf*
do
     if [ -r $qffile ]
     then
          if [ ! -s $qffile ]
          then
               echo -n " <zero: $qffile>" > /dev/console
               rm -f $qffile
          fi
     fi
done
# rename tf files to be qf if the qf does not exist
for tffile in tf*
do
     qffile=`echo $tffile | sed 's/t/q/'`
     if [ -r $tffile -a ! -f $qffile ]
     then
          echo -n " <recovering: $tffile>" > /dev/console
          mv $tffile $qffile
     else
          echo -n " <extra: $tffile>" > /dev/console
          rm -f $tffile
     fi
done
# remove df files with no corresponding qf files
for dffile in df*
do
     qffile=`echo $dffile | sed 's/d/q/'`
     if [ -r $dffile -a ! -f $qffile ]
     then
          echo -n " <incomplete: $dffile>" > /dev/console
          mv $dffile `echo $dffile | sed 's/d/D/'`
     fi
done
# announce files that have been saved during disaster recovery
for xffile in [A-Z]f*
do
     echo -n " <panic: $xffile>" > /dev/console
done

            Figure 1 -- A complex startup script
____________________________________________________________


              If you are not running a version of UNIX  that
         supports  Berkeley  TCP/IP,  do not include the --bbdd
         flag.












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      11..33..77..  //uussrr//lliibb//sseennddmmaaiill..hhff

              This is the help file used by  the  SMTP  HHEELLPP
         command.      It     should    be    copied    from
         "lib/sendmail.hf":

             cp lib/sendmail.hf /usr/lib

         The actual path of this file is defined  in  the  HH
         option of the _s_e_n_d_m_a_i_l_._c_f file.

      11..33..88..  //eettcc//sseennddmmaaiill..sstt

              If  you  wish to collect statistics about your
         mail  traffic,   you   should   create   the   file
         "/etc/sendmail.st":

             cp /dev/null /etc/sendmail.st
             chmod 666 /etc/sendmail.st

         This  file  does  not grow.  It is printed with the
         program "mailstats/mailstats.c."  The  actual  path
         of  this  file  is  defined  in the SS option of the
         _s_e_n_d_m_a_i_l_._c_f file.

      11..33..99..  //uussrr//bbiinn//mmaaiillqq

              If _s_e_n_d_m_a_i_l is invoked  as  "mailq,"  it  will
         simulate  the  --bbpp  flag (i.e., _s_e_n_d_m_a_i_l will print
         the contents of the mail queue; see  below).   This
         should be a link to /usr/sbin/sendmail.

22..  NNOORRMMAALL OOPPEERRAATTIIOONNSS

   22..11..  TThhee SSyysstteemm LLoogg

           The  system  log  is  supported by the _s_y_s_l_o_g_d(8)
      program.  All messages from _s_e_n_d_m_a_i_l are logged  under
      the LOG_MAIL facility5.

      22..11..11..  FFoorrmmaatt

              Each line in the  system  log  consists  of  a
         timestamp,  the  name of the machine that generated
         it (for logging  from  several  machines  over  the
         local  area  network),  the word "sendmail:", and a


____________________
   5Except  on  Ultrix, which does not support facilities in
the syslog.












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         message6.    Most   messages   are  a  sequence  of
         _n_a_m_e=_v_a_l_u_e pairs.

              The two most common lines are  logged  when  a
         message  is  processed.  The first logs the receipt
         of a message; there will be exactly  one  of  these
         per message.  Some fields may be omitted if they do
         not contain interesting information.  Fields are:

         from      The envelope sender address.

         size      The size of the message in bytes.

         class     The class (i.e., numeric  precedence)  of
                   the message.

         pri       The  initial  message  priority (used for
                   queue sorting).

         nrcpts    The number  of  envelope  recipients  for
                   this message (after aliasing and forward-
                   ing).

         msgid     The message id of the message  (from  the
                   header).

         proto     The protocol used to receive this message
                   (e.g., ESMTP or UUCP)

         relay     The machine from which it was received.

         There is also one line logged per delivery  attempt
         (so there can be several per message if delivery is
         deferred or there are multiple recipients).  Fields
         are:

         to        A  comma-separated list of the recipients
                   to this mailer.

         ctladdr   The ``controlling user'',  that  is,  the
                   name of the user whose credentials we use
                   for delivery.

         delay     The total delay  between  the  time  this
                   message  was received and the time it was
                   delivered.

         xdelay    The amount of time needed in this  deliv-
                   ery  attempt  (normally indicative of the
____________________
   6This format may vary slightly if your vendor has changed
the syntax.











SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--1177


                   speed of the connection).

         mailer    The name of the mailer used to deliver to
                   this recipient.

         relay     The   name  of  the  host  that  actually
                   accepted (or rejected) this recipient.

         stat      The delivery status.

         Not all fields are present  in  all  messages;  for
         example, the relay is not listed for local deliver-
         ies.

      22..11..22..  LLeevveellss

              If  you  have  _s_y_s_l_o_g_d(8)  or  an   equivalent
         installed,  you  will be able to do logging.  There
         is a  large  amount  of  information  that  can  be
         logged.   The  log  is  arranged as a succession of
         levels.  At the lowest level only extremely strange
         situations  are logged.  At the highest level, even
         the  most  mundane  and  uninteresting  events  are
         recorded  for posterity.  As a convention, log lev-
         els under ten are  considered  generally  "useful;"
         log levels above 64 are reserved for debugging pur-
         poses.  Levels from 11-64 are reserved for  verbose
         information that some sites might want.

              A  complete  description  of the log levels is
         given in section 4.6.

   22..22..  DDuummppiinngg SSttaattee

           You can ask _s_e_n_d_m_a_i_l to log a dump  of  the  open
      files and the connection cache by sending it a SIGUSR1
      signal.  The results are logged at LOG_DEBUG priority.

   22..33..  TThhee MMaaiill QQuueeuuee

           Sometimes  a host cannot handle a message immedi-
      ately.  For example, it may  be  down  or  overloaded,
      causing it to refuse connections.  The sending host is
      then expected to save this message in its  mail  queue
      and attempt to deliver it later.

           Under  normal  conditions  the mail queue will be
      processed transparently.  However, you may  find  that
      manual intervention is sometimes necessary.  For exam-
      ple, if a major host is down for a period of time  the
      queue  may become clogged.  Although _s_e_n_d_m_a_i_l ought to
      recover gracefully when the host  comes  up,  you  may
      find performance unacceptably bad in the meantime.










SSMMMM::0088--1188          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      22..33..11..  PPrriinnttiinngg tthhee qquueeuuee

              The contents of the queue can be printed using
         the _m_a_i_l_q command (or by specifying the --bbpp flag to
         _s_e_n_d_m_a_i_l):

             mailq

         This  will produce a listing of the queue id's, the
         size of the message, the date the  message  entered
         the queue, and the sender and recipients.

      22..33..22..  FFoorrcciinngg tthhee qquueeuuee

              _S_e_n_d_m_a_i_l should run the queue automatically at
         intervals.  The algorithm is to read and  sort  the
         queue,  and  then to attempt to process all jobs in
         order.  When it attempts to run the  job,  _s_e_n_d_m_a_i_l
         first  checks  to see if the job is locked.  If so,
         it ignores the job.

              There is no attempt to insure  that  only  one
         queue  processor exists at any time, since there is
         no guarantee that a job cannot take forever to pro-
         cess  (however, _s_e_n_d_m_a_i_l does include heuristics to
         try to abort jobs that are taking absurd amounts of
         time;  technically,  this  violates RFC 821, but is
         blessed by RFC 1123).  Due  to  the  locking  algo-
         rithm,  it  is impossible for one job to freeze the
         entire queue.  However, an uncooperative  recipient
         host  or a program recipient that never returns can
         accumulate many processes in your system.  Unfortu-
         nately, there is no completely general way to solve
         this.

              In some cases, you may find that a major  host
         going  down  for a couple of days may create a pro-
         hibitively large queue.  This will result in  _s_e_n_d_-
         _m_a_i_l  spending an inordinate amount of time sorting
         the queue.  This situation can be fixed  by  moving
         the  queue  to a temporary place and creating a new
         queue.  The old queue can be  run  later  when  the
         offending host returns to service.

              To  do  this,  it  is  acceptable  to move the
         entire queue directory:

             cd /var/spool
             mv mqueue omqueue; mkdir mqueue; chmod 700 mqueue

         You should then kill the existing daemon (since  it
         will  still  be  processing in the old queue direc-
         tory) and create a new daemon.










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--1199


              To run the old mail queue, run  the  following
         command:

             /usr/sbin/sendmail -oQ/var/spool/omqueue -q

         The --ooQQ flag specifies an alternate queue directory
         and the --qq flag says to just run every job  in  the
         queue.   If  you  have a tendency toward voyeurism,
         you can use the --vv flag to watch what is going  on.

              When  the  queue  is  finally emptied, you can
         remove the directory:

             rmdir /var/spool/omqueue


   22..44..  TThhee SSeerrvviiccee SSwwiittcchh

           The implementation  of  certain  system  services
      such as host and user name lookup is controlled by the
      service switch.  If the host operating system supports
      such  a  switch  _s_e_n_d_m_a_i_l will use the native version.
      Ultrix, Solaris, and DEC OSF/1 are  examples  of  such
      systems.

           If  the underlying operating system does not sup-
      port a service switch (e.g., SunOS, HP-UX,  BSD)  then
      _s_e_n_d_m_a_i_l will provide a stub implementation.  The SSeerr--
      vviicceeSSwwiittcchhFFiillee option points to the  name  of  a  file
      that  has  the  service  definitions Each line has the
      name of a service and the possible implementations  of
      that service.  For example, the file:

          hosts     dns files nis
          aliases   files nis

      will ask _s_e_n_d_m_a_i_l to look for hosts in the Domain Name
      System first.  If  the  requested  host  name  is  not
      found,  it  tries  local  files,  and if that fails it
      tries NIS.  Similarly, when  looking  for  aliases  it
      will try the local files first followed by NIS.

           Service  switches  are not completely integrated.
      For example, despite the  fact  that  the  host  entry
      listed  in the above example specifies to look in NIS,
      on SunOS this won't happen because the  system  imple-
      mentation of _g_e_t_h_o_s_t_b_y_n_a_m_e(3) doesn't understand this.
      If there is enough  demand  _s_e_n_d_m_a_i_l  may  reimplement
      _g_e_t_h_o_s_t_b_y_n_a_m_e(3),  _g_e_t_h_o_s_t_b_y_a_d_d_r(3),  _g_e_t_p_w_e_n_t(3), and
      the other system routines that would be  necessary  to
      make this work seamlessly.












SSMMMM::0088--2200          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


   22..55..  TThhee AAlliiaass DDaattaabbaassee

           The alias database exists in two forms.  One is a
      text form, maintained in the file  _/_e_t_c_/_a_l_i_a_s_e_s_.   The
      aliases are of the form

          name: name1, name2, ...

      Only local names may be aliased; e.g.,

          [e-mail]: [e-mail]

      will   not   have   the   desired  effect  (except  on
      prep.ai.MIT.EDU, and they probably  don't  want  me)7.
      Aliases  may be continued by starting any continuation
      lines with a space or a tab.  Blank  lines  and  lines
      beginning with a sharp sign ("#") are comments.

           The  second  form is processed by the _n_d_b_m(3)8 or
      _d_b(3)  library.    This   form   is   in   the   files
      _/_e_t_c_/_a_l_i_a_s_e_s_._d_i_r  and  _/_e_t_c_/_a_l_i_a_s_e_s_._p_a_g_.   This is the
      form that _s_e_n_d_m_a_i_l actually uses to  resolve  aliases.
      This technique is used to improve performance.

           The  control  of  search order is actually set by
      the service switch.  Essentially, the entry

          OAswitch:aliases

      is always added as the first alias  entry;  also,  the
      first  alias  file name without a class (e.g., without
      "nis:" on the front) will be used as the name  of  the
      file for a ``files'' entry in the aliases switch.  For
      example, if the configuration file contains

          OA/etc/aliases

      and the service switch contains

          aliases   nis files nisplus

      then  aliases  will  first  be  searched  in  the  NIS
      database,  then  in  /etc/aliases,  then  in  the NIS+
      database.


____________________
   7Actually, any mailer that has the `A'  mailer  flag  set
will  permit aliasing; this is normally limited to the local
mailer.
   8The _g_d_b_m package probably works as well.












SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--2211


           You can also  use  NIS-based  alias  files.   For
      example, the specification:

          OA/etc/aliases
          OAnis:[e-mail]

      will  first  search the /etc/aliases file and then the
      map named "mail.aliases" in "my.nis.domain".  Warning:
      if  you  build your own NIS-based alias files, be sure
      to provide the --ll flag to _m_a_k_e_d_b_m(8) to map upper case
      letters  in the keys to lower case; otherwise, aliases
      with upper case letters in  their  names  won't  match
      incoming addresses.

           Additional  flags  can  be  added after the colon
      exactly like a KK line -- for example:

          OAnis:-N [e-mail]

      will search the appropriate NIS map and always include
      null bytes in the key.

      22..55..11..  RReebbuuiillddiinngg tthhee aalliiaass ddaattaabbaassee

              The  DB  or DBM version of the database may be
         rebuilt explicitly by executing the command

             newaliases

         This is equivalent to giving _s_e_n_d_m_a_i_l the --bbii flag:

             /usr/sbin/sendmail -bi


              If the RReebbuuiillddAAlliiaasseess (old DD) option is speci-
         fied in the configuration,  _s_e_n_d_m_a_i_l  will  rebuild
         the  alias  database automatically if possible when
         it is out of date.  Auto-rebuild can  be  dangerous
         on  heavily loaded machines with large alias files;
         if it might take  more  than  the  rebuild  timeout
         (option  AAlliiaassWWaaiitt,  old  aa, which is normally five
         minutes) to rebuild the database, there is a chance
         that  several processes will start the rebuild pro-
         cess simultaneously.

              If you have multiple aliases databases  speci-
         fied,  the --bbii flag rebuilds all the database types
         it understands (for example, it  can  rebuild  NDBM
         databases but not NIS databases).














SSMMMM::0088--2222          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      22..55..22..  PPootteennttiiaall pprroobblleemmss

              There  are a number of problems that can occur
         with the alias database.  They all  result  from  a
         _s_e_n_d_m_a_i_l process accessing the DBM version while it
         is only partially built.  This can happen under two
         circumstances:  One  process  accesses the database
         while another process is rebuilding it, or the pro-
         cess  rebuilding  the  database  dies (due to being
         killed or a system  crash)  before  completing  the
         rebuild.

              Sendmail   has  three  techniques  to  try  to
         relieve these problems.  First, it  ignores  inter-
         rupts  while  rebuilding  the database; this avoids
         the problem of someone aborting the process leaving
         a partially rebuilt database.  Second, it locks the
         database source file during the rebuild -- but that
         may not work over NFS or if the file is unwritable.
         Third, at the end of the rebuild it adds  an  alias
         of the form

             @: @

         (which  is  not  normally  legal).  Before _s_e_n_d_m_a_i_l
         will access the database, it checks to insure  that
         this entry exists9.

      22..55..33..  LLiisstt oowwnneerrss

              If  an  error  occurs  on sending to a certain
         address, say "_x", _s_e_n_d_m_a_i_l will look for  an  alias
         of  the form "owner-_x" to receive the errors.  This
         is typically useful for a mailing  list  where  the
         submitter of the list has no control over the main-
         tenance of the list itself; in this case  the  list
         maintainer  would  be  the  owner of the list.  For
         example:

             unix-wizards: eric@ucbarpa, wnj@monet, nosuchuser,
                  sam@matisse
             owner-unix-wizards: unix-wizards-request
             unix-wizards-request: eric@ucbarpa

         would cause "eric@ucbarpa" to get  the  error  that
         will  occur  when someone sends to unix-wizards due
         to the inclusion of "nosuchuser" on the list.
____________________
   9The  AAlliiaassWWaaiitt  option  is required in the configuration
for this action to occur.  This should  normally  be  speci-
fied.












SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--2233


              List owners also  cause  the  envelope  sender
         address  to be modified.  The contents of the owner
         alias are used if they point to a single user, oth-
         erwise  the  name of the alias itself is used.  For
         this reason, and to obey Internet conventions,  the
         "owner-"  address normally points at the "-request"
         address; this causes messages to go  out  with  the
         typical   Internet   convention  of  using  ``_l_i_s_t-
         request'' as the return address.

   22..66..  UUsseerr IInnffoorrmmaattiioonn DDaattaabbaassee

           If you have a version of _s_e_n_d_m_a_i_l with  the  user
      information  database compiled in, and you have speci-
      fied one or more databases using  the  UU  option,  the
      databases  will be searched for a _u_s_e_r:maildrop entry.
      If found, the mail  will  be  sent  to  the  specified
      address.

   22..77..  PPeerr--UUsseerr FFoorrwwaarrddiinngg ((..ffoorrwwaarrdd FFiilleess))

           As an alternative to the alias database, any user
      may put a file with the name ".forward" in his or  her
      home  directory.   If this file exists, _s_e_n_d_m_a_i_l redi-
      rects mail for that user  to  the  list  of  addresses
      listed in the .forward file.  For example, if the home
      directory for user "mckusick" has a .forward file with
      contents:

          mckusick@ernie
          kirk@calder

      then  any  mail  arriving for "mckusick" will be redi-
      rected to the specified accounts.

           Actually,  the  configuration  file   defines   a
      sequence  of  filenames to check.  By default, this is
      the user's .forward file, but can  be  defined  to  be
      more  generally  using  the  JJ  option.  If you change
      this, you will have to inform your user  base  of  the
      change;  .forward is pretty well incorporated into the
      collective subconscious.

   22..88..  SSppeecciiaall HHeeaaddeerr LLiinneess

           Several header lines have special interpretations
      defined by the configuration file.  Others have inter-
      pretations built into _s_e_n_d_m_a_i_l that cannot be  changed
      without   changing   the  code.   These  builtins  are
      described here.













SSMMMM::0088--2244          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      22..88..11..  EErrrroorrss--TToo::

              If errors occur  anywhere  during  processing,
         this  header will cause error messages to go to the
         listed addresses.  This  is  intended  for  mailing
         lists.

              The  Errors-To:  header was created in the bad
         old days when UUCP didn't understand  the  distinc-
         tion  between  an envelope and a header; this was a
         hack to provide what should now be  passed  as  the
         envelope sender address.  It should go away.  It is
         only used if the UUsseeEErrrroorrssTToo option is set.

              The Errors-To: header is  official  deprecated
         and will go away in a future release.

      22..88..22..  AAppppaarreennttllyy--TToo::

              RFC  822 requires at least one recipient field
         (To:, Cc:, or Bcc: line) in every  message.   If  a
         message  comes  in with no recipients listed in the
         message then _s_e_n_d_m_a_i_l will adjust the header  based
         on the "NoRecipientAction" option.  One of the pos-
         sible actions is to add an "Apparently-To:"  header
         line  for  any  recipients it is aware of.  This is
         not put in as a standard recipient line to warn any
         recipients that the list is not complete.

              The  Apparently-To: header is non-standard and
         is deprecated.

      22..88..33..  PPrreecceeddeennccee

              The Precedence: header can be used as a  crude
         control  of  message  priority.  It tweaks the sort
         order in the queue and can be configured to  change
         the message timeout values.

   22..99..  IIDDEENNTT PPrroottooccooll SSuuppppoorrtt

           _S_e_n_d_m_a_i_l  supports  the IDENT protocol as defined
      in RFC 1413.  Although this enhances identification of
      the  author  of  an  email  message  by doing a ``call
      back'' to the originating system to include the  owner
      of  a  particular TCP connection in the audit trail it
      is in no sense perfect; a determined forger can easily
      spoof  the  IDENT protocol.  The following description
      is excerpted from RFC 1413:

           6.  Security Considerations












SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--2255


           The information returned by this protocol  is  at
           most  as  trustworthy as the host providing it OR
           the organization operating the host.   For  exam-
           ple,  a PC in an open lab has few if any controls
           on it to prevent a user from having this protocol
           return  any identifier the user wants.  Likewise,
           if the host has been compromised the  information
           returned may be completely erroneous and mislead-
           ing.

           The Identification Protocol is not intended as an
           authorization  or  access  control  protocol.  At
           best, it provides some additional auditing infor-
           mation  with  respect  to  TCP  connections.   At
           worst, it can provide misleading,  incorrect,  or
           maliciously incorrect information.

           The  use of the information returned by this pro-
           tocol for other than auditing  is  strongly  dis-
           couraged.    Specifically,  using  Identification
           Protocol information to make access control deci-
           sions  -  either  as the primary method (i.e., no
           other checks) or as an adjunct to  other  methods
           may  result  in  a weakening of normal host secu-
           rity.

           An Identification server may  reveal  information
           about users, entities, objects or processes which
           might normally be considered private.  An Identi-
           fication server provides service which is a rough
           analog of the CallerID services provided by  some
           phone companies and many of the same privacy con-
           siderations and arguments that apply to the  Cal-
           lerID  service  apply  to Identification.  If you
           wouldn't run a "finger"  server  due  to  privacy
           considerations  you may not want to run this pro-
           tocol.

      In some cases your system may not work  properly  with
      IDENT  support  due to a bug in the TCP/IP implementa-
      tion.  The symptoms will be that for  some  hosts  the
      SMTP connection will be closed almost immediately.  If
      this is true or if you do not want to use  IDENT,  you
      should  set  the IDENT timeout to zero; this will dis-
      able the IDENT protocol.

33..  AARRGGUUMMEENNTTSS

        The  complete  list  of  arguments  to  _s_e_n_d_m_a_i_l  is
   described  in detail in Appendix A.  Some important argu-
   ments are described here.












SSMMMM::0088--2266          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


   33..11..  QQuueeuuee IInntteerrvvaall

           The amount of time between forking a  process  to
      run  through  the queue is defined by the --qq flag.  If
      you run with delivery mode set to ii or bb this  can  be
      relatively  large, since it will only be relevant when
      a host that was down comes back up.  If you run  in  qq
      mode  it  should be relatively short, since it defines
      the maximum amount of time that a message may  sit  in
      the queue.  (See also the MinQueueAge option.)

           RFC  1123  section  5.3.1.1  says that this value
      should be at least 30 minutes (although that  probably
      doesn't make sense if you use ``queue-only'' mode).

   33..22..  DDaaeemmoonn MMooddee

           If  you  allow  incoming mail over an IPC connec-
      tion, you should have a daemon running.   This  should
      be  set  by your _/_e_t_c_/_r_c file using the --bbdd flag.  The
      --bbdd flag and the --qq flag may be combined in one call:

          /usr/sbin/sendmail -bd -q30m


           An alternative approach  is  to  invoke  sendmail
      from  _i_n_e_t_d(8)  (use  the  --bbss flag to ask sendmail to
      speak SMTP on its standard input  and  output).   This
      works and allows you to wrap _s_e_n_d_m_a_i_l in a TCP wrapper
      program, but may be a bit slower since the  configura-
      tion  file  has  to  be  re-read on every message that
      comes in.  If you do this, you still need  to  have  a
      _s_e_n_d_m_a_i_l running to flush the queue:

          /usr/sbin/sendmail -q30m


   33..33..  FFoorrcciinngg tthhee QQuueeuuee

           In  some  cases  you  may find that the queue has
      gotten clogged for some reason.  You can force a queue
      run  using  the --qq flag (with no value).  It is enter-
      taining to use the --vv flag (verbose) when this is done
      to watch what happens:

          /usr/sbin/sendmail -q -v


           You  can also limit the jobs to those with a par-
      ticular queue identifier, sender, or  recipient  using
      one  of  the queue modifiers.  For example, "-qRberke-
      ley" restricts the queue run to  jobs  that  have  the
      string  "berkeley"  somewhere  in one of the recipient










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--2277


      addresses.  Similarly, "-qSstring" limits the  run  to
      particular  senders  and "-qIstring" limits it to par-
      ticular queue identifiers.

   33..44..  DDeebbuuggggiinngg

           There are a fairly large number  of  debug  flags
      built into _s_e_n_d_m_a_i_l.  Each debug flag has a number and
      a level, where higher levels means to print  out  more
      information.   The  convention  is that levels greater
      than nine are "absurd," i.e., they print out  so  much
      information  that  you  wouldn't  normally want to see
      them except for debugging  that  particular  piece  of
      code.   Debug  flags  are set using the --dd option; the
      syntax is:

          debug-flag:   --dd debug-list
          debug-list:   debug-option [ , debug-option ]*
          debug-option: debug-range [ . debug-level ]
          debug-range:  integer | integer - integer
          debug-level:  integer

      where spaces are for reading ease only.  For example,

          -d12          Set flag 12 to level 1
          -d12.3        Set flag 12 to level 3
          -d3-17        Set flags 3 through 17 to level 1
          -d3-17.4      Set flags 3 through 17 to level 4

      For a complete list of the available debug  flags  you
      will have to look at the code (they are too dynamic to
      keep this documentation up to date).

   33..55..  CChhaannggiinngg tthhee VVaalluueess ooff OOppttiioonnss

           Options can be overridden using the --oo or --OO com-
      mand line flags.  For example,

          /usr/sbin/sendmail -oT2m

      sets  the  TT  (timeout) option to two minutes for this
      run only; the equivalent line using  the  long  option
      name is

          /usr/sbin/sendmail -OQueueTimeout=2m


           Some  options  have security implications.  Send-
      mail allows you to set  these,  but  relinquishes  its














SSMMMM::0088--2288          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      setuid root permissions thereafter10.

   33..66..  TTrryyiinngg aa DDiiffffeerreenntt CCoonnffiigguurraattiioonn FFiillee

           An alternative configuration file can  be  speci-
      fied using the --CC flag; for example,

          /usr/sbin/sendmail -Ctest.cf -oQ/tmp/mqueue

      uses  the  configuration  file  _t_e_s_t_._c_f instead of the
      default _/_e_t_c_/_s_e_n_d_m_a_i_l_._c_f_.  If the --CC flag has no value
      it defaults to _s_e_n_d_m_a_i_l_._c_f in the current directory.

           _S_e_n_d_m_a_i_l  gives  up  its  setuid root permissions
      when you use this flag, so it is common to use a  pub-
      licly  writable  directory (such as /tmp) as the spool
      directory (QueueDirectory or Q option) while  testing.

   33..77..  LLooggggiinngg TTrraaffffiicc

           Many  SMTP implementations do not fully implement
      the protocol.  For  example,  some  personal  computer
      based  SMTPs  do  not understand continuation lines in
      reply codes.  These can be very hard to trace.  If you
      suspect  such  a  problem, you can set traffic logging
      using the --XX flag.  For example,

          /usr/sbin/sendmail -X /tmp/traffic -bd

      will log all traffic in the file _/_t_m_p_/_t_r_a_f_f_i_c.

           This logs a lot of data very quickly  and  should
      NNEEVVEERR  be used during normal operations.  After start-
      ing up such a daemon, force the errant  implementation
      to  send  a message to your host.  All message traffic
      in and out of _s_e_n_d_m_a_i_l, including  the  incoming  SMTP
      traffic, will be logged in this file.

   33..88..  TTeessttiinngg CCoonnffiigguurraattiioonn FFiilleess

           When  you build a configuration table, you can do
      a certain amount of testing using the "test  mode"  of
      _s_e_n_d_m_a_i_l.  For example, you could invoke _s_e_n_d_m_a_i_l as:

          sendmail -bt -Ctest.cf

      which  would read the configuration file "test.cf" and
____________________
   10That  is,  it  sets  its effective uid to the real uid;
thus, if you are executing as root, as from  root's  crontab
file  or  during  system  startup  the root permissions will
still be honored.











SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--2299


      enter test mode.  In this mode, you enter lines of the
      form:

          rwset address

      where  _r_w_s_e_t  is the rewriting set you want to use and
      _a_d_d_r_e_s_s is an address to apply the set to.  Test  mode
      shows  you  the steps it takes as it proceeds, finally
      showing you the address it ends up with.  You may  use
      a comma separated list of rwsets for sequential appli-
      cation of rules to an input.  For example:

          3,1,21,4 monet:bollard

      first   applies   ruleset   three   to    the    input
      "monet:bollard."   Ruleset  one is then applied to the
      output of ruleset three, followed similarly  by  rule-
      sets twenty-one and four.

           If  you  need  more  detail, you can also use the
      "-d21" flag to turn on more debugging.  For example,

          sendmail -bt -d21.99

      turns on an incredible amount of information; a single
      word  address  is  probably going to print out several
      pages worth of information.

           You should be warned  that  internally,  _s_e_n_d_m_a_i_l
      applies  ruleset 3 to all addresses.  In test mode you
      will have to do that  manually.   For  example,  older
      versions allowed you to use

          0 [e-mail]

      This version requires that you use:

          3,0 [e-mail]


           As of version 8.7, some other syntaxes are avail-
      able in test mode:

       +o .Dxvalue defines macro  _x  to  have  the  indicated
         _v_a_l_u_e.   This  is  useful when debugging rules that
         use the $$&&_x syntax.
       +o .Ccvalue adds the indicated _v_a_l_u_e to class _c.
       +o .Sruleset dumps the contents of the indicated rule-
         set.
       +o -ddebug-spec  is  equivalent  to  the  command-line
         flag.












SSMMMM::0088--3300          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


44..  TTUUNNIINNGG

        There are a number of configuration  parameters  you
   may want to change, depending on the requirements of your
   site.  Most of these are set using an option in the  con-
   figuration   file.    For  example,  the  line  "O  Time-
   out.queuereturn=5d" sets option "Timeout.queuereturn"  to
   the value "5d" (five days).

        Most  of these options have appropriate defaults for
   most sites.  However, sites having very high  mail  loads
   may  find they need to tune them as appropriate for their
   mail load.  In particular,  sites  experiencing  a  large
   number  of small messages, many of which are delivered to
   many recipients, may find that they need  to  adjust  the
   parameters dealing with queue priorities.

        All  versions  of  _s_e_n_d_m_a_i_l  prior to 8.7 had single
   character option names.  As of  8.7,  options  have  long
   (multi-character  names).   Although  old short names are
   still accepted, most new options do not have short equiv-
   alents.

        This section only describes the options you are most
   likely to want to tweak; read section 5 for more details.

   44..11..  TTiimmeeoouuttss

           All time intervals are set using a scaled syntax.
      For example, "10m"  represents  ten  minutes,  whereas
      "2h30m" represents two and a half hours.  The full set
      of scales is:

          s   seconds
          m   minutes
          h   hours
          d   days
          w   weeks


      44..11..11..  QQuueeuuee iinntteerrvvaall

              The argument to  the  --qq  flag  specifies  how
         often  a  sub-daemon  will  run the queue.  This is
         typically set to between fifteen  minutes  and  one
         hour.   RFC  1123  section  5.3.1.1 recommends that
         this be at least 30 minutes.

      44..11..22..  RReeaadd ttiimmeeoouuttss

              Timeouts  all   have   option   names   "Time-
         out._s_u_b_o_p_t_i_o_n".   The  recognized _s_u_b_o_p_t_i_o_ns, their
         default values, and the minimum values  allowed  by










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--3311


         RFC 1123 section 5.3.2 are:

         connect   The  time  to wait for an SMTP connection
                   to open (the _c_o_n_n_e_c_t(2) system call)  [0,
                   unspecified].   If  zero, uses the kernel
                   default.  In  no  case  can  this  option
                   extend the timeout longer than the kernel
                   provides, but it can shorten it.  This is
                   to  get  around  kernels  that provide an
                   absurdly long connection timeout (90 min-
                   utes in one case).

         initial   The  wait  for  the  initial 220 greeting
                   message [5m, 5m].

         helo      The wait for a reply from a HELO or  EHLO
                   command   [5m,  unspecified].   This  may
                   require a host name lookup, so five  min-
                   utes is probably a reasonable minimum.

         mail      The  wait for a reply from a MAIL command
                   [10m, 5m].

         rcpt      The wait for a reply from a RCPT  command
                   [1h, 5m].  This should be long because it
                   could be pointing at a list that takes  a
                   long time to expand (see below).

         datainit  The  wait for a reply from a DATA command
                   [5m, 2m].

         datablock The wait for reading a data  block  (that
                   is,  the body of the message).  [1h, 3m].
                   This  should  be  long  because  it  also
                   applies to programs piping input to _s_e_n_d_-
                   _m_a_i_l which have no guarantee  of  prompt-
                   ness.

         datafinal The  wait for a reply from the dot termi-
                   nating a message.  [1h, 10m].  If this is
                   shorter than the time actually needed for
                   the  receiver  to  deliver  the  message,
                   duplicates  will  be  generated.  This is
                   discussed in RFC 1047.

         rset      The wait for a reply from a RSET  command
                   [5m, unspecified].

         quit      The  wait for a reply from a QUIT command
                   [2m, unspecified].

         misc      The wait for a reply  from  miscellaneous
                   (but  short)  commands  such as NOOP (no-










SSMMMM::0088--3322          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


                   operation)  and  VERB  (go  into  verbose
                   mode).  [2m, unspecified].

         command   In  server  SMTP,  the  time  to wait for
                   another command.  [1h, 5m].

         ident     The timeout waiting for  a  reply  to  an
                   IDENT query [30s11, unspecified].

         For compatibility with old configuration files,  if
         no  _s_u_b_o_p_t_i_o_n is specified, all the timeouts marked
         with  are set to the indicated value.

              Many of the RFC 1123 minimum values  may  well
         be too short.  _S_e_n_d_m_a_i_l was designed to the RFC 822
         protocols, which did  not  specify  read  timeouts;
         hence,  versions  of  _s_e_n_d_m_a_i_l prior to version 8.1
         did not guarantee to reply  to  messages  promptly.
         In  particular, a "RCPT" command specifying a mail-
         ing list will expand and verify the entire list;  a
         large  list  on  a slow system may easily take more
         than five minutes12.  I recommend a one hour  time-
         out  --  since  a communications failure during the
         RCPT phase is rare, a long timeout is  not  onerous
         and  may  ultimately  help  reduce network load and
         duplicated messages.

              For example, the lines:

             O Timeout.command=25m
             O Timeout.datablock=3h

         sets the server SMTP command timeout to 25  minutes
         and the input data block timeout to three hours.

      44..11..33..  MMeessssaaggee ttiimmeeoouuttss

              After  sitting  in the queue for a few days, a
         message will time out.  This is to insure  that  at
         least  the sender is aware of the inability to send
         a message.  The timeout is typically  set  to  five
         days.   It  is  sometimes  considered convenient to
         also send a warning message if the  message  is  in
         the  queue  longer  than  a few hours (assuming you
         normally have good connectivity; if  your  messages
____________________
   11On  some systems the default is zero to turn the proto-
col off entirely.
   12This verification includes  looking  up  every  address
with  the name server; this involves network delays, and can
in some cases can be considerable.












SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--3333


         normally  took  several  hours to send you wouldn't
         want to do this because it wouldn't be  an  unusual
         event).   These  timeouts  are  set using the TTiimmee--
         oouutt..qquueeuueerreettuurrnn and  TTiimmeeoouutt..qquueeuueewwaarrnn  options  in
         the  configuration  file  (previously both were set
         using the TT option).

              Since these options are global, and since  you
         can not know _a _p_r_i_o_r_i how long another host outside
         your domain will be down, a  five  day  timeout  is
         recommended.   This  allows  a recipient to fix the
         problem even if it occurs at  the  beginning  of  a
         long  weekend.   RFC 1123 section 5.3.1.1 says that
         this parameter should be ``at least 4-5 days''.

              The TTiimmeeoouutt..qquueeuueewwaarrnn value can be piggybacked
         on  the TT option by indicating a time after which a
         warning message should be sent;  the  two  timeouts
         are separated by a slash.  For example, the line

             OT5d/4h

         causes email to fail after five days, but a warning
         message will be sent after four hours.  This should
         be  large  enough  that  the message will have been
         tried several times.

   44..22..  FFoorrkkiinngg DDuurriinngg QQuueeuuee RRuunnss

           By setting the FFoorrkkEEaacchhJJoobb (YY)  option,  _s_e_n_d_m_a_i_l
      will fork before each individual message while running
      the queue.  This will prevent _s_e_n_d_m_a_i_l from  consuming
      large  amounts  of memory, so it may be useful in mem-
      ory-poor environments.  However,  if  the  FFoorrkkEEaacchhJJoobb
      option  is  not set, _s_e_n_d_m_a_i_l will keep track of hosts
      that are down during a queue run,  which  can  improve
      performance dramatically.

           If  the  FFoorrkkEEaacchhJJoobb  option is set, _s_e_n_d_m_a_i_l can
      not use connection caching.

   44..33..  QQuueeuuee PPrriioorriittiieess

           Every message is assigned a priority when  it  is
      first instantiated, consisting of the message size (in
      bytes) offset by the message class  (which  is  deter-
      mined  from  the  Precedence:  header) times the "work
      class factor" and the number of recipients  times  the
      "work  recipient  factor."   The  priority  is used to
      order the queue.  Higher numbers for the priority mean
      that  the message will be processed later when running
      the queue.











SSMMMM::0088--3344          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


           The message size is included so that  large  mes-
      sages  are  penalized relative to small messages.  The
      message class allows users  to  send  "high  priority"
      messages  by  including a "Precedence:" field in their
      message; the value of this field is looked up in the PP
      lines  of the configuration file.  Since the number of
      recipients affects the amount of load a  message  pre-
      sents  to  the  system, this is also included into the
      priority.

           The recipient and class factors can be set in the
      configuration  file  using the RReecciippiieennttFFaaccttoorr (yy) and
      CCllaassssFFaaccttoorr (zz) options respectively.  They default to
      30000  (for  the  recipient  factor) and 1800 (for the
      class factor).  The initial priority is:

     _p_r_i=_m_s_g_s_i_z_e-(_c_l_a_s_sxCCllaassssFFaaccttoorr))+(_n_r_c_p_txRReecciippiieennttFFaaccttoorr))

      (Remember, higher values for this  parameter  actually
      mean  that  the  job will be treated with lower prior-
      ity.)

           The priority of a job can also be  adjusted  each
      time it is processed (that is, each time an attempt is
      made to deliver it) using the "work time factor,"  set
      by  the  RReettrryyFFaaccttoorr (ZZ) option.  This is added to the
      priority, so it normally decreases the  precedence  of
      the  job,  on  the  grounds that jobs that have failed
      many times will tend to fail again in the future.  The
      RReettrryyFFaaccttoorr option defaults to 90000.

   44..44..  LLooaadd LLiimmiittiinngg

           _S_e_n_d_m_a_i_l  can be asked to queue (but not deliver)
      mail if the system load average gets  too  high  using
      the QQuueeuueeLLAA (xx) option.  When the load average exceeds
      the value of the QQuueeuueeLLAA option, the delivery mode  is
      set  to  qq  (queue only) if the QQuueeuueeFFaaccttoorr (qq) option
      divided by the difference in the current load  average
      and  the  QQuueeuueeLLAA option plus one exceeds the priority
      of the message -- that is, the message is queued iff:

                        _p_r_i>_L__QQ_A__uu-__eeQQ__uuuu__eeee__FFuu__aaee__ccLL__ttAA__oo+__rr1____

      The QQuueeuueeFFaaccttoorr option defaults  to  600000,  so  each
      point  of load average is worth 600000 priority points
      (as described above).

           For  drastic  cases,  the  RReeffuusseeLLAA  (XX)   option
      defines  a  load average at which _s_e_n_d_m_a_i_l will refuse
      to accept network connections.  Locally generated mail
      (including incoming UUCP mail) is still accepted.











SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--3355


   44..55..  DDeelliivveerryy MMooddee

           There  are  a number of delivery modes that _s_e_n_d_-
      _m_a_i_l can operate in, set by the DDeelliivveerryyMMooddee (dd)  con-
      figuration  option.   These  modes specify how quickly
      mail will be delivered.  Legal modes are:

          i   deliver interactively (synchronously)
          b   deliver in background (asynchronously)
          q   queue only (don't deliver)
          d   defer delvery attempts (don't deliver)

      There are tradeoffs.  Mode "i" gives  the  sender  the
      quickest  feedback, but may slow down some mailers and
      is hardly ever necessary.  Mode "b" delivers  promptly
      but can cause large numbers of processes if you have a
      mailer that takes a long time to  deliver  a  message.
      Mode "q" minimizes the load on your machine, but means
      that delivery may be  delayed  for  up  to  the  queue
      interval.   Mode  "d"  is identical to mode "q" except
      that it also prevents all the early map  lookups  from
      working;  it  is intended for ``dial on demand'' sites
      where DNS lookups might cost real money.  Some  simple
      error  messages  (e.g.,  host  unknown during the SMTP
      protocol) will be delayed using this mode.   Mode  "b"
      is the usual default.

           If you run in mode "q" (queue only), "d" (defer),
      or "b"  (deliver  in  background)  _s_e_n_d_m_a_i_l  will  not
      expand  aliases and follow .forward files upon initial
      receipt of the mail.  This speeds up the  response  to
      RCPT  commands.   Mode  "i" cannot be used by the SMTP
      server.

   44..66..  LLoogg LLeevveell

           The level of logging can  be  set  for  _s_e_n_d_m_a_i_l.
      The  default  using  a standard configuration table is
      level 9.  The levels are as follows:

      0    No logging.

      1    Serious system failures  and  potential  security
           problems.

      2    Lost communications (network problems) and proto-
           col failures.

      3    Other serious failures.

      4    Minor failures.












SSMMMM::0088--3366          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      5    Message collection statistics.

      6    Creation of error messages, VRFY  and  EXPN  com-
           mands.

      7    Delivery failures (host or user unknown, etc.).

      8    Successful    deliveries   and   alias   database
           rebuilds.

      9    Messages being deferred  (due  to  a  host  being
           down, etc.).

      10   Database  expansion  (alias,  forward, and userdb
           lookups).

      20   Logs attempts to run locked queue  files.   These
           are not errors, but can be useful to note if your
           queue appears to be clogged.

      30   Lost  locks  (only  if  using  lockf  instead  of
           flock).

      Additionally,   values   above  64  are  reserved  for
      extremely verbose debugging output.   No  normal  site
      would ever set these.

   44..77..  FFiillee MMooddeess

           The modes used for files depend on what function-
      ality you want and the level of security you  require.

      44..77..11..  TToo ssuuiidd oorr nnoott ttoo ssuuiidd??

              _S_e_n_d_m_a_i_l  can  safely  be made setuid to root.
         At the point where it is about to _e_x_e_c(2) a mailer,
         it  checks  to see if the userid is zero; if so, it
         resets the userid and groupid to a default (set  by
         the  uu  and gg options).  (This can be overridden by
         setting the SS flag to the mailer for  mailers  that
         are  trusted and must be called as root.)  However,
         this will cause mail  processing  to  be  accounted
         (using _s_a(8)) to root rather than to the user send-
         ing the mail.

              If you don't make _s_e_n_d_m_a_i_l setuid to root,  it
         will  still run but you lose a lot of functionality
         and a lot of privacy, since you'll have to make the
         queue  directory  world  readable.   You could also
         make _s_e_n_d_m_a_i_l setuid  to  some  pseudo-user  (e.g.,
         create  a  user called "sendmail" and make _s_e_n_d_m_a_i_l
         setuid to that) which will fix the privacy problems
         but not the functionality issues.  Also, this isn't










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--3377


         a guarantee of security: for  example,  root  occa-
         sionally  sends  mail, and the daemon often runs as
         root.

      44..77..22..  SShhoouulldd mmyy aalliiaass ddaattaabbaassee bbee wwrriittaabbllee??

              At  Berkeley  we  have  the   alias   database
         (/etc/aliases*)  mode  644.   While  this is not as
         flexible as if  the  database  were  more  666,  it
         avoids  potential security problems with a globally
         writable database.

              The database that _s_e_n_d_m_a_i_l  actually  used  is
         represented   by  the  two  files  _a_l_i_a_s_e_s_._d_i_r  and
         _a_l_i_a_s_e_s_._p_a_g (both in /etc) (or  _a_l_i_a_s_e_s_._d_b  if  you
         are  running  with the new Berkeley database primi-
         tives).  The mode on these files should  match  the
         mode  on  /etc/aliases.  If _a_l_i_a_s_e_s is writable and
         the DBM files  (_a_l_i_a_s_e_s_._d_i_r  and  _a_l_i_a_s_e_s_._p_a_g)  are
         not,  users will be unable to reflect their desired
         changes through to the actual  database.   However,
         if  _a_l_i_a_s_e_s  is  read-only  and  the  DBM files are
         writable, a slightly sophisticated user can arrange
         to steal mail anyway.

              If  your  DBM  files  are  not writable by the
         world or you do not have auto-rebuild enabled (with
         the  AAuuttooRReebbuuiillddAAlliiaasseess  option),  then you must be
         careful to reconstruct the alias database each time
         you change the text version:

             newaliases

         If  this  step is ignored or forgotten any intended
         changes will also be ignored or forgotten.

   44..88..  CCoonnnneeccttiioonn CCaacchhiinngg

           When processing the queue, _s_e_n_d_m_a_i_l will  try  to
      keep  the  last  few  open  connections  open to avoid
      startup and shutdown costs.  This only applies to  IPC
      connections.

           When  trying  to  open  a connection the cache is
      first searched.  If an open connection is found, it is
      probed  to see if it is still active by sending a NOOP
      command.  It is not an error if this  fails;  instead,
      the connection is closed and reopened.

           Two parameters control the connection cache.  The
      CCoonnnneeccttiioonnCCaacchheeSSiizzee (kk) option defines the  number  of
      simultaneous  open connections that will be permitted.
      If it is set to zero, connections will  be  closed  as










SSMMMM::0088--3388          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      quickly as possible.  The default is one.  This should
      be set as appropriate for your system  size;  it  will
      limit  the  amount  of  system resources that _s_e_n_d_m_a_i_l
      will use during queue runs.   Never  set  this  higher
      than 4.

           The  CCoonnnneeccttiioonnCCaacchheeTTiimmeeoouutt  (KK) option specifies
      the maximum time that any cached  connection  will  be
      permitted  to  idle.   When the idle time exceeds this
      value the connection is closed.  This number should be
      small (under ten minutes) to prevent you from grabbing
      too many resources from other hosts.  The  default  is
      five minutes.

   44..99..  NNaammee SSeerrvveerr AAcccceessss

           Control  of  host  address  lookups is set by the
      hhoossttss service entry in your service switch  file.   If
      you  are  on a system that has built-in service switch
      support (e.g., Ultrix, Solaris,  or  DEC  OSF/1)  then
      your  system  is probably configured properly already.
      Otherwise,   _s_e_n_d_m_a_i_l   will    consult    the    file
      //eettcc//sseerrvviiccee..sswwiittcchh,  which  should be created.  _S_e_n_d_-
      _m_a_i_l only uses two entries: hhoossttss and aalliiaasseess.

           However, some systems (such as SunOS) will do DNS
      lookups  regardless  of  the  setting  of  the service
      switch entry.  In particular, the system routine _g_e_t_h_-
      _o_s_t_b_y_n_a_m_e(3)  is  used to look up host names, and many
      vendor versions try some combination of DNS, NIS,  and
      file lookup in /etc/hosts without consulting a service
      switch.  _S_e_n_d_m_a_i_l makes no attempt to work around this
      problem,  and  the DNS lookup will be done anyway.  If
      you do not have a nameserver configured at  all,  such
      as  at  a UUCP-only site, _s_e_n_d_m_a_i_l will get a "connec-
      tion refused" message when it tries to connect to  the
      name  server.   If the hhoossttss switch entry has the ser-
      vice "dns" listed somewhere in the list, _s_e_n_d_m_a_i_l will
      interpret  this  to  mean a temporary failure and will
      queue the mail for  later  processing;  otherwise,  it
      ignores the name server data.

           The  same  technique is used to decide whether to
      do MX lookups.  If you want MX support, you _m_u_s_t  have
      "dns" listed as a service in the hhoossttss switch entry.

           The  RReessoollvveerrOOppttiioonnss  (II)  option  allows  you to
      tweak name server options.  The command line  takes  a
      series of flags as documented in _r_e_s_o_l_v_e_r(3) (with the
      leading "RES_" deleted).  Each can be preceded  by  an
      optional `+' or `-'.  For example, the line

          O ResolverOptions=+AAONLY -DNSRCH










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--3399


      turns  on  the  AAONLY  (accept  authoritative answers
      only) and turns off  the  DNSRCH  (search  the  domain
      path)   options.    Most  resolver  libraries  default
      DNSRCH, DEFNAMES, and RECURSE flags on and all  others
      off.   You can also include "HasWildcardMX" to specify
      that there is  a  wildcard  MX  record  matching  your
      domain;  this  turns  off MX matching when canonifying
      names, which can  lead  to  inappropriate  canonifica-
      tions.

           Version  level  1  configurations turn DNSRCH and
      DEFNAMES off when doing delivery  lookups,  but  leave
      them  on  everywhere  else.   Version  8  of  _s_e_n_d_m_a_i_l
      ignores them when doing canonification  lookups  (that
      is, when using $[ ... $]), and always does the search.
      If you don't want  to  do  automatic  name  extension,
      don't call $[ ... $].

           The  search rules for $[ ... $] are somewhat dif-
      ferent than usual.  If the name being looked up has at
      least  one  dot,  it  always tries the unmodified name
      first.  If that fails, it  tries  the  reduced  search
      path,  and  lastly tries the unmodified name (but only
      for names without a dot, since names with a  dot  have
      already  been  tried).   This  allows  names  such  as
      ``utc.CS'' to match the site in Czechoslovakia  rather
      than  the  site in your local Computer Science depart-
      ment.  It also prefers A and  CNAME  records  over  MX
      records  -- that is, if it finds an MX record it makes
      note of it, but keeps looking.  This way, if you  have
      a wildcard MX record matching your domain, it will not
      assume that all names match.

           To completely turn off all name server access  on
      systems without service switch support (such as SunOS)
      you will have to  recompile  with  -DNAMED_BIND=0  and
      remove  -lresolv  from  the  list  of  libraries to be
      searched when linking.

   44..1100..  MMoovviinngg tthhee PPeerr--UUsseerr FFoorrwwaarrdd FFiilleess

           Some sites mount each user's home directory  from
      a  local  disk  on  their  workstation,  so that local
      access is fast.  However, the result is that  .forward
      file  lookups  are slow.  In some cases, mail can even
      be delivered on machines inappropriately because of  a
      file  server being down.  The performance can be espe-
      cially bad if you run the automounter.

           The FFoorrwwaarrddPPaatthh (JJ) option allows you  to  set  a
      path  of  forward files.  For example, the config file
      line











SSMMMM::0088--4400          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


          O ForwardPath=/var/forward/$u:$z/.forward.$w

      would first look for a file with the same name as  the
      user's login in /var/forward; if that is not found (or
      is inaccessible) the file ``.forward._m_a_c_h_i_n_e_n_a_m_e''  in
      the  user's  home directory is searched.  A truly per-
      verse site could also search by sender  by  using  $r,
      $s, or $f.

           If  you  create a directory such as /var/forward,
      it should be mode 1777 (that is, the sticky bit should
      be set).  Users should create the files mode 644.

   44..1111..  FFrreeee SSppaaccee

           On  systems  that have one of the system calls in
      the _s_t_a_t_f_s(2) family (including  _s_t_a_t_v_f_s  and  _u_s_t_a_t),
      you can specify a minimum number of free blocks on the
      queue filesystem using the MMiinnFFrreeeeBBlloocckkss  (bb)  option.
      If there are fewer than the indicated number of blocks
      free on the filesystem on which the queue  is  mounted
      the  SMTP  server  will reject mail with the 452 error
      code.  This invites  the  SMTP  client  to  try  again
      later.

           Beware  of  setting  this option too high; it can
      cause rejection of email when that mail would be  pro-
      cessed without difficulty.

   44..1122..  MMaaxxiimmuumm MMeessssaaggee SSiizzee

           To  avoid  overflowing  your  system with a large
      message, the MMaaxxMMeessssaaggeeSSiizzee option can be set  to  set
      an  absolute  limit  on  the  size of any one message.
      This will be advertised  in  the  ESMTP  dialogue  and
      checked during message collection.

   44..1133..  PPrriivvaaccyy FFllaaggss

           The  PPrriivvaaccyyOOppttiioonnss  (pp) option allows you to set
      certain ``privacy'' flags.   Actually,  many  of  them
      don't  give you any extra privacy, rather just insist-
      ing that client SMTP  servers  use  the  HELO  command
      before  using certain commands or adding extra headers
      to indicate possible spoof attempts.

           The option takes a  series  of  flag  names;  the
      final privacy is the inclusive or of those flags.  For
      example:

          O PrivacyOptions=needmailhelo, noexpn

      insists that the HELO or EHLO command be used before a










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--4411


      MAIL  command  is  accepted and disables the EXPN com-
      mand.

           The flags are detailed in section 5.1.6.

   44..1144..  SSeenndd ttoo MMee TToooo

           Normally, _s_e_n_d_m_a_i_l deletes the (envelope)  sender
      from  any  list  expansions.   For  example, if "matt"
      sends to a list that contains "matt"  as  one  of  the
      members he won't get a copy of the message.  If the --mm
      (me too) command line flag, or if the MMeeTToooo (mm) option
      is  set  in  the configuration file, this behaviour is
      suppressed.  Some sites like to run  the  SMTP  daemon
      with --mm.

55..  TTHHEE WWHHOOLLEE SSCCOOOOPP OONN TTHHEE CCOONNFFIIGGUURRAATTIIOONN FFIILLEE

        This  section  describes  the  configuration file in
   detail.

        There is one point that should be made clear immedi-
   ately:  the  syntax of the configuration file is designed
   to be reasonably easy to parse, since this is done  every
   time  _s_e_n_d_m_a_i_l starts up, rather than easy for a human to
   read or write.  On the "future project" list is a config-
   uration-file compiler.

        The  configuration  file is organized as a series of
   lines, each of  which  begins  with  a  single  character
   defining  the  semantics for the rest of the line.  Lines
   beginning with a space or a tab  are  continuation  lines
   (although  the  semantics  are  not  well defined in many
   places).  Blank lines and lines beginning  with  a  sharp
   symbol (`#') are comments.

   55..11..  RR aanndd SS ---- RReewwrriittiinngg RRuulleess

           The  core  of  address  parsing are the rewriting
      rules.  These are an ordered production system.  _S_e_n_d_-
      _m_a_i_l  scans through the set of rewriting rules looking
      for a match on the left hand side (LHS) of  the  rule.
      When  a  rule  matches, the address is replaced by the
      right hand side (RHS) of the rule.

           There are several sets of rewriting rules.   Some
      of  the  rewriting  sets  are used internally and must
      have specific semantics.  Other rewriting sets do  not
      have  specifically assigned semantics, and may be ref-
      erenced by the mailer definitions or by other  rewrit-
      ing sets.












SSMMMM::0088--4422          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


           The syntax of these two commands are:

          SS_n

      Sets the current ruleset being collected to _n.  If you
      begin a ruleset more than once it deletes the old def-
      inition.

          RR_l_h_s _r_h_s _c_o_m_m_e_n_t_s

      The fields must be separated by at least one tab char-
      acter; there may be embedded  spaces  in  the  fields.
      The _l_h_s is a pattern that is applied to the input.  If
      it matches, the input is rewritten to  the  _r_h_s.   The
      _c_o_m_m_e_n_t_s are ignored.

           Macro  expansions  of  the  form $$_x are performed
      when the configuration file is  read.   Expansions  of
      the  form  $$&&_x are performed at run time using a some-
      what less general algorithm.   This  for  is  intended
      only for referencing internally defined macros such as
      $$hh that are changed at runtime.

      55..11..11..  TThhee lleefftt hhaanndd ssiiddee

              The left hand side of rewriting rules contains
         a   pattern.    Normal  words  are  simply  matched
         directly.  Metasyntax is introduced using a  dollar
         sign.  The metasymbols are:

             $$**   Match zero or more tokens
             $$++   Match one or more tokens
             $$--   Match exactly one token
             $$==_x  Match any phrase in class _x
             $$~~_x  Match any word not in class _x

         If  any  of  these  match, they are assigned to the
         symbol $$_n for replacement on the right  hand  side,
         where  _n  is the index in the LHS.  For example, if
         the LHS:

             $-:$+

         is applied to the input:

             UCBARPA:eric

         the rule will match, and the values passed  to  the
         RHS will be:

             $1  UCBARPA
             $2  eric











SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--4433


              Additionally,  the LHS can include $$@@ to match
         zero tokens.  This is _n_o_t bound to a $$_n on the RHS,
         and  is  normally only used when it stands alone in
         order to match the null input.

      55..11..22..  TThhee rriigghhtt hhaanndd ssiiddee

              When the left hand side of  a  rewriting  rule
         matches,  the  input is deleted and replaced by the
         right hand side.  Tokens are copied  directly  from
         the  RHS  unless  they  begin  with  a dollar sign.
         Metasymbols are:

             $$_n         Substitute indefinite token _n from LHS
             $$[[_n_a_m_e$$]]   Canonicalize _n_a_m_e
             $$((_m_a_p _k_e_y $$@@_a_r_g_u_m_e_n_t_s $$::_d_e_f_a_u_l_t $$))
                        Generalized keyed mapping function
             $$>>_n        "Call" ruleset _n
             $$##_m_a_i_l_e_r   Resolve to _m_a_i_l_e_r
             $$@@_h_o_s_t     Specify _h_o_s_t
             $$::_u_s_e_r     Specify _u_s_e_r


              The $$_n syntax  substitutes  the  corresponding
         value  from  a  $$++,  $$--, $$**, $$==, or $$~~ match on the
         LHS.  It may be used anywhere.

              A host name enclosed  between  $$[[  and  $$]]  is
         looked  up  in the host database(s) and replaced by
         the canonical name13.  For example, "$[ftp$]" might
         become          "ftp.CS.Berkeley.EDU"           and
         "$[[128.32.130.2]$]"     would     become     "van-
         gogh.CS.Berkeley.EDU."   _S_e_n_d_m_a_i_l  recognizes  it's
         numeric  IP address without calling the name server
         and replaces it with it's canonical name.

              The $$(( ...  $$)) syntax is a more  general  form
         of  lookup;  it  uses  a  named  map  instead of an
         implicit map.  If no lookup is found, the indicated
         _d_e_f_a_u_l_t is inserted; if no default is specified and
         no lookup matches, the  value  is  left  unchanged.
         The  _a_r_g_u_m_e_n_t_s  are  passed to the map for possible
         use.

              The $$>>_n syntax causes  the  remainder  of  the
         line  to be substituted as usual and then passed as
         the argument to ruleset  _n.   The  final  value  of
         ruleset  _n  then  becomes the substitution for this
____________________
   13This is actually completely equivalent to $(host  _h_o_s_t_-
_n_a_m_e$).  In particular, a $$:: default can be used.












SSMMMM::0088--4444          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


         rule.  The $$>> syntax can only be used at the begin-
         ning of the right hand side; it can be only be pre-
         ceded by $$@@ or $$::.

              The $$## syntax should _o_n_l_y be used  in  ruleset
         zero  or  a  subroutine of ruleset zero.  It causes
         evaluation of the ruleset to terminate immediately,
         and  signals  to _s_e_n_d_m_a_i_l that the address has com-
         pletely resolved.  The complete syntax is:

             $$##_m_a_i_l_e_r $$@@_h_o_s_t $$::_u_s_e_r

         This specifies the  {mailer,  host,  user}  3-tuple
         necessary  to  direct the mailer.  If the mailer is
         local  the  host part may be omitted14.  The _m_a_i_l_e_r
         must be a single word, but the _h_o_s_t and _u_s_e_r may be
         multi-part.   If  the  _m_a_i_l_e_r  is  the  builtin IPC
         mailer, the _h_o_s_t may be a colon-separated  list  of
         hosts  that  are  searched  in  order for the first
         working address (exactly  like  MX  records).   The
         _u_s_e_r  is  later  rewritten  by  the mailer-specific
         envelope rewriting  set  and  assigned  to  the  $$uu
         macro.   As  a  special case, if the value to $$## is
         "local" and the first character of the $$:: value  is
         "@",  the "@" is stripped off, and a flag is set in
         the address descriptor that causes sendmail to  not
         do ruleset 5 processing.

              Normally, a rule that matches is retried, that
         is, the rule loops until it fails.  A RHS may  also
         be  preceded  by a $$@@ or a $$:: to change this behav-
         ior.  A $$@@ prefix causes the ruleset to return with
         the remainder of the RHS as the value.  A $$:: prefix
         causes the rule to terminate immediately,  but  the
         ruleset to continue; this can be used to avoid con-
         tinued  application  of  a  rule.   The  prefix  is
         stripped before continuing.

              The  $$@@ and $$:: prefixes may precede a $$>> spec;
         for example:

             R$+     $: $>7 $1

         matches anything, passes that to ruleset seven, and
         continues; the $$:: is necessary to avoid an infinite
         loop.
____________________
   14You may want to use it for special  "per  user"  exten-
sions.   For  example, in the address "[e-mail]"; the
"+foo" part is not part of the user name, and is  passed  to
the local mailer for local use.












SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--4455


              Substitution occurs in  the  order  described,
         that  is,  parameters from the LHS are substituted,
         hostnames  are  canonicalized,  "subroutines"   are
         called, and finally $$##, $$@@, and $$:: are processed.

      55..11..33..  SSeemmaannttiiccss ooff rreewwrriittiinngg rruullee sseettss

              There  are  five rewriting sets that have spe-
         cific semantics.  Four  of  these  are  related  as
         depicted by figure 1.

              Ruleset  three  should  turn  the address into
         "canonical form."  This form should have the  basic
         syntax:

             local-part@host-domain-spec

         Ruleset  three  is applied by _s_e_n_d_m_a_i_l before doing
         anything with any address.

              If no "@" sign is specified,  then  the  host-
         domain-spec  _m_a_y  be appended (box "D" in Figure 1)
         from the sender address (if the CC flag  is  set  in
         the  mailer definition corresponding to the _s_e_n_d_i_n_g
         mailer).

              Ruleset zero is applied after ruleset three to
         addresses that are going to actually specify recip-
         ients.  It must resolve to a _{_m_a_i_l_e_r_,  _h_o_s_t_,  _u_s_e_r_}
         triple.   The  _m_a_i_l_e_r must be defined in the mailer

____________________________________________________________

                    +---+
                 -->| 0 |-->resolved address
                /   +---+
               /            +---+   +---+
              /        ---->| 1 |-->| S |--
       +---+ / +---+  /     +---+   +---+  \    +---+
addr-->| 3 |-->| D |--                      --->| 4 |-->msg
       +---+   +---+  \     +---+   +---+  /    +---+
                        --->| 2 |-->| R |--
                            +---+   +---+

            Figure 1 -- Rewriting set semantics
          D -- sender domain addition
          S -- mailer-specific sender rewriting
          R -- mailer-specific recipient rewriting
____________________________________________________________














SSMMMM::0088--4466          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


         definitions from the configuration file.  The  _h_o_s_t
         is  defined  into  the $$hh macro for use in the argv
         expansion of the specified mailer.

              Rulesets one and two are applied to all sender
         and  recipient  addresses  respectively.   They are
         applied before any specification in the mailer def-
         inition.  They must never resolve.

              Ruleset  four  is  applied to all addresses in
         the message.  It is  typically  used  to  translate
         internal to external form.

      55..11..44..  IIPPCC mmaaiilleerrss

              Some  special processing occurs if the ruleset
         zero resolves to an IPC mailer (that is,  a  mailer
         that  has  "[IPC]" listed as the Path in the MM con-
         figuration line.  The host name passed  after  "$@"
         has  MX expansion performed; this looks the name up
         in DNS to find alternate delivery sites.

              The host name can also be provided as a dotted
         quad in square brackets; for example:

             [128.32.149.78]

         This  causes direct conversion of the numeric value
         to a TCP/IP host address.

              The host name passed in  after  the  "$@"  may
         also  be  a colon-separated list of hosts.  Each is
         separately MX expanded and the results are concate-
         nated  to make (essentially) one long MX list.  The
         intent here is to create "fake" MX records that are
         not published in DNS for private internal networks.

              As a final special case, the host name can  be
         passed in as a text string in square brackets:

             [ucbvax.berkeley.edu]

         This  form  avoids  the  MX mapping.  NN..BB..:: _T_h_i_s _i_s
         _i_n_t_e_n_d_e_d _o_n_l_y _f_o_r _s_i_t_u_a_t_i_o_n_s _w_h_e_r_e _y_o_u _h_a_v_e _a  _n_e_t_-
         _w_o_r_k  _f_i_r_e_w_a_l_l  _o_r  _o_t_h_e_r _h_o_s_t _t_h_a_t _w_i_l_l _d_o _s_p_e_c_i_a_l
         _p_r_o_c_e_s_s_i_n_g _f_o_r _a_l_l  _y_o_u_r  _m_a_i_l_,  _s_o  _t_h_a_t  _y_o_u_r  _M_X
         _r_e_c_o_r_d  _p_o_i_n_t_s  _t_o  _a _g_a_t_e_w_a_y _m_a_c_h_i_n_e_; _t_h_i_s _m_a_c_h_i_n_e
         _c_o_u_l_d _t_h_e_n _d_o _d_i_r_e_c_t _d_e_l_i_v_e_r_y  _t_o  _m_a_c_h_i_n_e_s  _w_i_t_h_i_n
         _y_o_u_r  _l_o_c_a_l  _d_o_m_a_i_n_.   _U_s_e _o_f _t_h_i_s _f_e_a_t_u_r_e _d_i_r_e_c_t_l_y
         _v_i_o_l_a_t_e_s _R_F_C _1_1_2_3 _s_e_c_t_i_o_n _5_._3_._5_: _i_t _s_h_o_u_l_d  _n_o_t  _b_e
         _u_s_e_d _l_i_g_h_t_l_y_.












SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--4477


   55..22..  DD ---- DDeeffiinnee MMaaccrroo

           Macros  are named with a single character or with
      a word in {braces}.  Single  character  names  may  be
      selected  from  the entire ASCII set, but user-defined
      macros should be selected from the set of  upper  case
      letters  only.  Lower case letters and special symbols
      are used internally.   Long  names  beginning  with  a
      lower  case  letter  or  a  punctuation  character are
      reserved for use by  sendmail,  so  user-defined  long
      macro names should begin with an upper case letter.

           The syntax for macro definitions is:

          DD_x_v_a_l

      where  _x is the name of the macro (which may be a sin-
      gle character or a word in  braces)  and  _v_a_l  is  the
      value it should have.  There should be no spaces given
      that do not actually belong in the macro value.

           Macros are interpolated using the  construct  $$_x,
      where  _x  is the name of the macro to be interpolated.
      This interpolation is done when the configuration file
      is read, except in MM lines.  The special construct $$&&_x
      can be used in RR lines to get deferred  interpolation.

           Conditionals can be specified using the syntax:

          $?x text1 $| text2 $.

      This  interpolates  _t_e_x_t_1  if the macro $$xx is set, and
      _t_e_x_t_2 otherwise.  The "else" ($$||) clause may be  omit-
      ted.

           Lower  case macro names are reserved to have spe-
      cial semantics, used to pass information in or out  of
      _s_e_n_d_m_a_i_l,  and special characters are reserved to pro-
      vide conditionals, etc.  Upper case names (that is, $$AA
      through  $$ZZ)  are specifically reserved for configura-
      tion file authors.

           The following  macros  are  defined  and/or  used
      internally  by  _s_e_n_d_m_a_i_l for interpolation into argv's
      for mailers or for other contexts.   The  ones  marked
      are  information  passed  into  sendmail15,  the  ones
      marked  are information passed  both  in  and  out  of
      sendmail,  and  the  unmarked macros are passed out of
____________________
   15As  of version 8.6, all of these macros have reasonable
defaults.  Previous versions required that they be  defined.












SSMMMM::0088--4488          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      sendmail but are not otherwise used internally.  These
      macros are:

      $a   The  origination date in RFC 822 format.  This is
           extracted from the Date: line.

      $b   The current date in RFC 822 format.

      $c   The hop count.  This is a count of the number  of
           Received:  lines plus the value of the --hh command
           line flag.

      $d   The current date in UNIX (ctime) format.

      $e   (Obsolete;   use    SmtpGreetingMessage    option
           instead.)   The  SMTP  entry  message.   This  is
           printed out when SMTP starts up.  The first  word
           must  be  the  $$jj  macro  as specified by RFC821.
           Defaults to "$j Sendmail $v ready at  $b".   Com-
           monly redefined to include the configuration ver-
           sion number, e.g., "$j Sendmail  $v/$Z  ready  at
           $b"

      $f   The envelope sender (from) address.

      $g   The  sender  address  relative  to the recipient.
           For  example,  if  $$ff  is  "foo",  $$gg   will   be
           "host!foo",  "[e-mail]",  or  whatever  is
           appropriate for the receiving mailer.

      $h   The recipient host.  This is  set  in  ruleset  0
           from the $# field of a parsed address.

      $i   The queue id, e.g., "HAA12345".

      $j   The  "official"  domain name for this site.  This
           is fully qualified if the full qualification  can
           be  found.   It _m_u_s_t be redefined to be the fully
           qualified domain name if your system is not  con-
           figured so that information can find it automati-
           cally.

      $k   The UUCP node name (from the uname system  call).

      $l   (Obsolete; use UnixFromLine option instead.)  The
           format of the UNIX from line.   Unless  you  have
           changed  the  UNIX mailbox format, you should not
           change the default, which is "From $g  $d".

      $m   The domain part of the _g_e_t_h_o_s_t_n_a_m_e return  value.
           Under  normal  circumstances, $$jj is equivalent to
           $$ww..$$mm.











SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--4499


      $n   The name of  the  daemon  (for  error  messages).
           Defaults to "MAILER-DAEMON".

      $o   (Obsolete:  use  OperatorChars  option  instead.)
           The set of "operators" in addresses.  A  list  of
           characters  which  will  be considered tokens and
           which will separate tokens  when  doing  parsing.
           For  example,  if  "@" were in the $$oo macro, then
           the input "a@b" would be scanned as three tokens:
           "a," "@," and "b."  Defaults to ".:@[]", which is
           the minimum set necessary to do RFC 822  parsing;
           a  richer  set  of operators is ".:%@!/[]", which
           adds support for  UUCP,  the  %-hack,  and  X.400
           addresses.

      $p   Sendmail's process id.

      $q   Default  format  of sender address.  The $$qq macro
           specifies how an address should appear in a  mes-
           sage  when  it is defaulted.  Defaults to "<$g>".
           It is commonly redefined to be "$?x$x <$g>$|$g$."
           or "$g$?x ($x)$.", corresponding to the following
           two formats:

               Eric Allman <[e-mail]>
               [e-mail] (Eric Allman)

           _S_e_n_d_m_a_i_l properly quotes names that have  special
           characters if the first form is used.

      $r   Protocol  used  to receive the message.  Set from
           the --pp command line flag or by  the  SMTP  server
           code.

      $s   Sender's host name.  Set from the --pp command line
           flag or by the SMTP server code.

      $t   A numeric representation of the current time.

      $u   The recipient user.

      $v   The version number of the _s_e_n_d_m_a_i_l binary.

      $w   The hostname of this site.  This is the root name
           of this host (but see below for caveats).

      $x   The full name of the sender.

      $z   The home directory of the recipient.

      $_   The validated sender address.












SSMMMM::0088--5500          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


           There  are three types of dates that can be used.
      The $$aa and $$bb macros are in RFC 822 format; $$aa is  the
      time as extracted from the "Date:" line of the message
      (if there was one), and $$bb is  the  current  date  and
      time  (used  for  postmarks).   If  no "Date:" line is
      found in the incoming message, $$aa is set to  the  cur-
      rent  time also.  The $$dd macro is equivalent to the $$bb
      macro in UNIX (ctime) format.

           The macros $$ww, $$jj, and $$mm are set to the identity
      of this host.  _S_e_n_d_m_a_i_l tries to find the fully quali-
      fied name of the host if at all possible; it does this
      by  calling _g_e_t_h_o_s_t_n_a_m_e(2) to get the current hostname
      and then passing that  to  _g_e_t_h_o_s_t_b_y_n_a_m_e(3)  which  is
      supposed  to return the canonical version of that host
      name.16 Assuming this is successful, $$jj is set to  the
      fully  qualified name and $$mm is set to the domain part
      of the name (everything after the first dot).  The  $$ww
      macro  is set to the first word (everything before the
      first dot) if you have a level 5 or higher  configura-
      tion  file;  otherwise, it is set to the same value as
      $$jj.  If the canonification is not  successful,  it  is
      imperative  that  the  config file set $$jj to the fully
      qualified domain name17.

           The  $$ff  macro  is the id of the sender as origi-
      nally determined; when mailing to a specific host  the
      $$gg  macro is set to the address of the sender _r_e_l_a_t_i_v_e
      _t_o _t_h_e _r_e_c_i_p_i_e_n_t_.  For example, if  I  send  to  "bol-
      [e-mail]"  from  the machine "van-
      gogh.CS.Berkeley.EDU" the $$ff macro will be "eric"  and
      the $$gg macro will be "[e-mail]."

           The  $$xx  macro  is  set  to  the full name of the
      sender.  This can be determined in several  ways.   It
      can  be passed as flag to _s_e_n_d_m_a_i_l.  It can be defined
      in the NAME environment variable.  The third choice is
      the value of the "Full-Name:" line in the header if it
      exists, and the fourth choice is the comment field  of
      a "From:" line.  If all of these fail, and if the mes-
      sage is being originated locally,  the  full  name  is
      looked up in the _/_e_t_c_/_p_a_s_s_w_d file.

           When  sending,  the $$hh, $$uu, and $$zz macros get set
      to the host, user, and home directory  (if  local)  of
____________________
   16For example, on some systems _g_e_t_h_o_s_t_n_a_m_e  might  return
"foo"  which  would be mapped to "foo.bar.com" by _g_e_t_h_o_s_t_b_y_-
_n_a_m_e.
   17Older versions of sendmail didn't pre-define $$jj at all,
so up until 8.6, config files _a_l_w_a_y_s had to define $$jj.












SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--5511


      the  recipient.  The first two are set from the $$@@ and
      $$:: part of the rewriting rules, respectively.

           The $$pp and $$tt macros are used  to  create  unique
      strings  (e.g.,  for the "Message-Id:" field).  The $$ii
      macro is set to the queue id on this host; if put into
      the  timestamp  line  it  can  be extremely useful for
      tracking messages.  The $$vv macro is set to be the ver-
      sion  number  of  _s_e_n_d_m_a_i_l;  this  is  normally put in
      timestamps and has been proven  extremely  useful  for
      debugging.

           The $$cc field is set to the "hop count," i.e., the
      number of times this message has been processed.  This
      can  be  determined by the --hh flag on the command line
      or by counting the timestamps in the message.

           The $$rr and $$ss fields are set to the protocol used
      to communicate with _s_e_n_d_m_a_i_l and the sending hostname.
      They can be set together using  the  --pp  command  line
      flag or separately using the --MM or --ooMM flags.

           The  $$__  is  set to a validated sender host name.
      If the sender is running an RFC 1413  compliant  IDENT
      server  and the receiver has the IDENT protocol turned
      on, it will include the user name on that host.

   55..33..  CC aanndd FF ---- DDeeffiinnee CCllaasssseess

           Classes of phrases may be defined to match on the
      left hand side of rewriting rules, where a "phrase" is
      a sequence of characters that  do  not  contain  space
      characters.   For  example  a class of all local names
      for this site might be created  so  that  attempts  to
      send  to  oneself can be eliminated.  These can either
      be defined directly in the configuration file or  read
      in  from  another file.  Classes are named as a single
      letter or a word in {braces}.  Class  names  beginning
      with  lower  case  letters  and special characters are
      reserved for system use.  Classes  defined  in  config
      files  may  be  given names from the set of upper case
      letters for short names or  beginning  with  an  upper
      case letter for long names.

           The syntax is:

          CC_c_p_h_r_a_s_e_1 _p_h_r_a_s_e_2_._._.
          FF_c_f_i_l_e

      The first form defines the class _c to match any of the
      named words.  It is permissible to  split  them  among
      multiple lines; for example, the two forms:











SSMMMM::0088--5522          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


          CHmonet ucbmonet

      and

          CHmonet
          CHucbmonet

      are  equivalent.  The ``F'' form reads the elements of
      the class _c from the named _f_i_l_e.

           Elements of classes  can  be  accessed  in  rules
      using  $$==  or $$~~.  The $$~~ (match entries not in class)
      only matches a single word; multi-word entries in  the
      class are ignored in this context.

           The  class  $$==ww is set to be the set of all names
      this host is known by.  This  can  be  used  to  match
      local hostnames.

           The  class  $$==kk is set to be the same as $$kk, that
      is, the UUCP node name.

           The class $$==mm is set to the  set  of  domains  by
      which this host is known, initially just $$mm.

           The  class $$==tt is set to the set of trusted users
      by the TT configuration line.   If  you  want  to  read
      trusted users from a file use FFtt_/_f_i_l_e_/_n_a_m_e.

           The  class $$==nn can be set to the set of MIME body
      types that can never be eight to  seven  bit  encoded.
      It  defaults  to  "multipart/signed".   Message  types
      "message/*"  and  "multipart/*"  are   never   encoded
      directly.    Multipart  messages  are  always  handled
      recursively.  The handling of message/*  messages  are
      controlled  by  class $$==ss.  The class $$==ee contains the
      Content-Transfer-Encodings  that  can  be   8->7   bit
      encoded.   It is predefined to contain "7bit", "8bit",
      and "binary".  The class $$==ss contains the set of  sub-
      types  of message that can be treated recursively.  By
      default it contains only "rfc822".  Other  "message/*"
      types  cannot  be 8->7 bit encoded.  If a message con-
      taining eight bit data is sent to a  seven  bit  host,
      and that message cannot be encoded into seven bits, it
      will be stripped to 7 bits.

           _S_e_n_d_m_a_i_l can be  compiled  to  allow  a  _s_c_a_n_f(3)
      string  on  the  FF  line.  This lets you do simplistic
      parsing of text files.  For example, to read  all  the
      user  names  in  your  system  _/_e_t_c_/_p_a_s_s_w_d file into a
      class, use

          FL/etc/passwd %[^:]










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--5533


      which reads every line up to the first colon.

   55..44..  MM ---- DDeeffiinnee MMaaiilleerr

           Programs and interfaces to mailers are defined in
      this line.  The format is:

          MM_n_a_m_e, {_f_i_e_l_d=_v_a_l_u_e}*

      where  _n_a_m_e is the name of the mailer (used internally
      only) and the "field=name" pairs define attributes  of
      the mailer.  Fields are:

          Path      The pathname of the mailer
          Flags     Special flags for this mailer
          Sender    Rewriting set(s) for sender addresses
          Recipient Rewriting set(s) for recipient addresses
          Argv      An argument vector to pass to this mailer
          Eol       The end-of-line string for this mailer
          Maxsize   The maximum message length to this mailer
          Linelimit The maximum line length in the message body
          Directory The working directory for the mailer
          Userid    The default user and group id to run as
          Nice      The nice(2) increment for the mailer
          Charset   The default character set for 8-bit characters
          Type      The MTS type information (used for error messages)

      Only the first character of the field name is checked.

           The following flags may  be  set  in  the  mailer
      description.   Any  other  flags may be used freely to
      conditionally assign headers to messages destined  for
      particular  mailers.  Flags marked with are not inter-
      preted by the _s_e_n_d_m_a_i_l binary; these are  the  conven-
      tionally used to correlate to the flags portion of the
      HH line.  Flags marked with apply to  the  mailers  for
      the  sender  address  rather  than the usual recipient
      mailers.

      a   Run Extended SMTP  (ESMTP)  protocol  (defined  in
          RFCs 1651, 1652, and 1653).  This flag defaults on
          if the SMTP greeting  message  includes  the  word
          "ESMTP".

      A   Look  up the user part of the address in the alias
          database.  Normally this is  only  set  for  local
          mailers.

      b   Force  a blank line on the end of a message.  This
          is intended to work around some stupid versions of
          /bin/mail  that  require  a blank line, but do not
          provide it themselves.  It would not  normally  be
          used on network mail.










SSMMMM::0088--5544          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      c   Do not include comments in addresses.  This should
          only be used if you have to work around  a  remote
          mailer  that  gets  confused  by  comments.   This
          strips addresses of the form "Phrase <address>" or
          "address (Comment)" down to just "address".

      C   If  mail  is _r_e_c_e_i_v_e_d from a mailer with this flag
          set, any addresses in the header that do not  have
          an  at sign ("@") after being rewritten by ruleset
          three will have  the  "@domain"  clause  from  the
          sender  envelope  address  tacked on.  This allows
          mail with headers of the form:

              From: usera@hosta
              To: userb@hostb, userc

          to be rewritten as:

              From: usera@hosta
              To: userb@hostb, userc@hosta

          automatically.  However, it  doesn't  really  work
          reliably.

      D   This mailer wants a "Date:" header line.

      e   This  mailer is expensive to connect to, so try to
          avoid connecting normally; any  necessary  connec-
          tion will occur during a queue run.

      E   Escape  lines beginning with "From" in the message
          with a `>' sign.

      f   The mailer wants a --ff _f_r_o_m flag, but only if  this
          is  a  network forward operation (i.e., the mailer
          will give an error if the executing user does  not
          have special permissions).

      F   This mailer wants a "From:" header line.

      g   Normally,   _s_e_n_d_m_a_i_l  sends  internally  generated
          email (e.g., error messages) using the null return
          address  as  required  by RFC 1123.  However, some
          mailers don't accept a null  return  address.   If
          necessary, you can set the gg flag to prevent _s_e_n_d_-
          _m_a_i_l from obeying the  standards;  error  messages
          will  be sent as from the MAILER-DAEMON (actually,
          the value of the $$nn macro).

      h   Upper case should be preserved in host  names  for
          this mailer.












SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--5555


      I   This mailer will be speaking SMTP to another _s_e_n_d_-
          _m_a_i_l -- as such it can use special  protocol  fea-
          tures.  This option is not required (i.e., if this
          option is  omitted  the  transmission  will  still
          operate  successfully,  although  perhaps  not  as
          efficiently as possible).

      k   Normally when _s_e_n_d_m_a_i_l  connects  to  a  host  via
          SMTP, it checks to make sure that this isn't acci-
          dently the same host name as might happen if _s_e_n_d_-
          _m_a_i_l  is  misconfigured  or if a long-haul network
          interface is set in loopback mode.  This flag dis-
          ables  the loopback check.  It should only be used
          under very unusual circumstances.

      K   Currently unimplemented.  Reserved for chunking.

      l   This mailer is local (i.e., final delivery will be
          performed).

      L   Limit  the  line  lengths  as specified in RFC821.
          This deprecated option should be replaced  by  the
          LL==  mail declaration.  For historic reasons, the LL
          flag also sets the 77 flag.

      m   This mailer can send to multiple users on the same
          host  in  one transaction.  When a $$uu macro occurs
          in the _a_r_g_v part of the  mailer  definition,  that
          field will be repeated as necessary for all quali-
          fying users.

      M   This mailer wants a "Message-Id:" header line.

      n   Do not insert a  UNIX-style  "From"  line  on  the
          front of the message.

      o   Always  run as the owner of the recipient mailbox.
          Normally _s_e_n_d_m_a_i_l runs as the sender  for  locally
          generated  mail or as "daemon" (actually, the user
          specified in the uu option) when delivering network
          mail.   The  normal  behaviour is required by most
          local mailers, which will not allow  the  envelope
          sender address to be set unless the mailer is run-
          ning as daemon.  This flag is  ignored  if  the  SS
          flag is set.

      p   Use  the route-addr style reverse-path in the SMTP
          "MAIL FROM:" command rather than just  the  return
          address;  although this is required in RFC821 sec-
          tion 3.1, many hosts do not process  reverse-paths
          properly.   Reverse-paths  are officially discour-
          aged by RFC 1123.











SSMMMM::0088--5566          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      P   This mailer wants a "Return-Path:" line.

      r   Same as ff, but sends a --rr flag.

      s   Strip quote  characters  ("  and  \)  off  of  the
          address before calling the mailer.

      S   Don't  reset the userid before calling the mailer.
          This would be used in a secure  environment  where
          _s_e_n_d_m_a_i_l ran as root.  This could be used to avoid
          forged addresses.  If the UU== field is also  speci-
          fied,  this  flag  causes the user id to always be
          set to that user and group (instead of leaving  it
          as root).

      u   Upper  case  should be preserved in user names for
          this mailer.

      U   This mailer wants UUCP-style "From" lines with the
          ugly "remote from <host>" on the end.

      w   The  user  must  have  a  valid  account  on  this
          machine, i.e., getpwnam must succeed.  If not, the
          mail  is  bounced.  This is required to get ".for-
          ward" capability.

      x   This mailer wants a "Full-Name:" header line.

      X   This mailer want to use the hidden  dot  algorithm
          as specified in RFC821; basically, any line begin-
          ning with a dot will have an extra  dot  prepended
          (to  be  stripped at the other end).  This insures
          that lines in the message containing  a  dot  will
          not terminate the message prematurely.

      5   If no aliases are found for this address, pass the
          address through ruleset 5 for  possible  alternate
          resolution.   This is intended to forward the mail
          to an alternate delivery spot.

      7   Strip all output  to  seven  bits.   This  is  the
          default  if the LL flag is set.  Note that clearing
          this option is not sufficient to  get  full  eight
          bit data passed through _s_e_n_d_m_a_i_l.  If the 77 option
          is set, this is essentially always set, since  the
          eighth  bit was stripped on input.  Note that this
          option will only impact messages that didn't  have
          8->7 bit MIME conversions performed.

      8   If set, it is acceptable to send eight bit data to
          this mailer; the usual attempt to do 8->7 bit MIME
          conversions will be bypassed.











SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--5577


      :   Check  addresses to see if they begin ":include:";
          if  they  do,  convert  them  to  the  "*include*"
          mailer.

      |   Check  addresses  to see if they begin with a `|';
          if they do, convert them to the "prog" mailer.

      /   Check addresses to see if they begin with  a  `/';
          if they do, convert them to the "*file*" mailer.

      @   Look up addresses in the user database.

           Configuration  files  prior to level 6 assume the
      `A', `w', `5', `:', `|', `/', and `@' options  on  the
      mailer named "local".

           The  mailer  with the special name "error" can be
      used to generate a user error.   The  (optional)  host
      field  is  an exit status to be returned, and the user
      field is a message to be printed.  The exit status may
      be numeric or one of the values USAGE, NOUSER, NOHOST,
      UNAVAILABLE, SOFTWARE, TEMPFAIL, PROTOCOL,  or  CONFIG
      to  return the corresponding EX_ exit code.  For exam-
      ple, the entry:

          $#error $@ NOHOST $: Host unknown in this domain

      on the RHS of a rule will cause the specified error to
      be  generated and the "Host unknown" exit status to be
      returned if the LHS  matches.   This  mailer  is  only
      functional in rulesets zero or five.

           The mailer named "local" _m_u_s_t be defined in every
      configuration file.  This is  used  to  deliver  local
      mail, and is treated specially in several ways.  Addi-
      tionally, three other mailers named "prog",  "*file*",
      and "*include*" may be defined to tune the delivery of
      messages  to  programs,  files,  and  :include:  lists
      respectively.  They default to:

          Mprog, P=/bin/sh, F=lsD, A=sh -c $u
          M*file*, P=/dev/null, F=lsDFMPEu, A=FILE
          M*include*, P=/dev/null, F=su, A=INCLUDE


           The  Sender  and  Recipient  rewriting  sets  may
      either be a simple ruleset id or may be two ids  sepa-
      rated  by  a  slash; if so, the first rewriting set is
      applied  to  envelope  addresses  and  the  second  is
      applied to headers.

           The  Directory is actually a colon-separated path
      of directories to try.  For  example,  the  definition










SSMMMM::0088--5588          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      "D=$z:/"  first  tries  to  execute in the recipient's
      home directory; if that is not available, it tries  to
      execute  in  the  root  of  the  filesystem.   This is
      intended to be used only on the "prog"  mailer,  since
      some  shells  (such  as _c_s_h) refuse to execute if they
      cannot read  the  home  directory.   Since  the  queue
      directory  is  not  normally  readable by unprivileged
      users _c_s_h scripts as recipients can fail.

           The Userid specifies the default user  and  group
      id  to  run  as,  overriding  the  DDeeffaauullttUUsseerr  option
      (q.v.).  If the SS mailer flag is also specified,  this
      is  the user and group to run as in all circumstances.
      This may be given as _u_s_e_r_:_g_r_o_u_p to set both  the  user
      and  group  id; either may be an integer or a symbolic
      name to be looked up in the  _p_a_s_s_w_d  and  _g_r_o_u_p  files
      respectively.   If only a symbolic user name is speci-
      fied, the group id in the _p_a_s_s_w_d file for that user is
      used as the group id.

           The  Charset field is used when converting a mes-
      sage to MIME; this is the character set  used  in  the
      Content-Type:   header.   If  this  is  not  set,  the
      DDeeffaauullttCChhaarrsseett option is used, and if that is not set,
      the value "unknown-8bit" is used.  WWAARRNNIINNGG:: this field
      applies to the sender's mailer,  not  the  recipient's
      mailer.   For  example, if the envelope sender address
      lists an address on the local network and the  recipi-
      ent  is on an external network, the character set will
      be set from the Charset= field for the  local  network
      mailer, not that of the external network mailer.

           The Type= field sets the type information used in
      MIME error messages as defined by  RFC  XXX  (not  yet
      published).   It is actually three values separated by
      slashes: the MTA-type (that is, the description of how
      hosts are named), the address type (the description of
      e-mail  addresses),  and  the  diagnostic  type   (the
      description of error diagnostic codes).  Each of these
      must be a registered value or begin  with  "X-".   The
      default is "dns/rfc822/smtp".

   55..55..  HH ---- DDeeffiinnee HHeeaaddeerr

           The  format  of  the  header  lines that _s_e_n_d_m_a_i_l
      inserts into the message are defined by  the  HH  line.
      The syntax of this line is:

          HH[??_m_f_l_a_g_s??]_h_n_a_m_e:: _h_t_e_m_p_l_a_t_e

      Continuation lines in this spec are reflected directly
      into the outgoing message.   The  _h_t_e_m_p_l_a_t_e  is  macro
      expanded  before  insertion  into the message.  If the










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--5599


      _m_f_l_a_g_s (surrounded by question marks)  are  specified,
      at  least one of the specified flags must be stated in
      the mailer definition for this header to be  automati-
      cally output.  If one of these headers is in the input
      it is reflected to  the  output  regardless  of  these
      flags.

           Some  headers have special semantics that will be
      described later.

   55..66..  OO ---- SSeett OOppttiioonn

           There are a number of global options that can  be
      set  from  a  configuration  file.  Options are repre-
      sented by full words; some are also  representable  as
      single  characters for back compatibility.  The syntax
      of this line is:

          OO  _o_p_t_i_o_n==_v_a_l_u_e

      This sets option _o_p_t_i_o_n to be _v_a_l_u_e.  Note that  there
      _m_u_s_t be a space between the letter `O' and the name of
      the option.  An older version is:

          OO_o_v_a_l_u_e

      where the option _o is a single  character.   Depending
      on  the  option,  _v_a_l_u_e may be a string, an integer, a
      boolean (with legal values "t", "T", "f", or "F";  the
      default is TRUE), or a time interval.

           The  options supported (with the old, one charac-
      ter names in brackets) are:

      AliasFile=_s_p_e_c_, _s_p_e_c_, _._._.
                [A] Specify possible  alias  file(s).   Each
                _s_p_e_c should be in the format ``_c_l_a_s_s:: _f_i_l_e''
                where _c_l_a_s_s:: is  optional  and  defaults  to
                ``implicit''.   Depending on how _s_e_n_d_m_a_i_l is
                compiled,  valid  classes   are   "implicit"
                (search  through a compiled-in list of alias
                file types, for back compatibility),  "hash"
                (if  NEWDB  is specified), "dbm" (if NDBM is
                specified), "stab" (internal symbol table --
                not  normally  used unless you have no other
                database lookup), or "nis" (if NIS is speci-
                fied).   If  a  list  of _s_p_e_cs are provided,
                _s_e_n_d_m_a_i_l searches them in order.

      AliasWait=_t_i_m_e_o_u_t
                [a]  If  set,  wait  up  to  _t_i_m_e_o_u_t  (units
                default  to  minutes)  for an "@:@" entry to
                exist in the alias database before  starting










SSMMMM::0088--6600          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


                up.   If  it  does not appear in the _t_i_m_e_o_u_t
                interval  rebuild  the  database   (if   the
                AAuuttooRReebbuuiillddAAlliiaasseess  option  is  also set) or
                issue a warning.

      AutoRebuildAliases
                [D] If set, rebuild the  alias  database  if
                necessary  and  possible.  If this option is
                not set, _s_e_n_d_m_a_i_l  will  never  rebuild  the
                alias  database  unless explicitly requested
                using --bbii.  Not  recommended  --  can  cause
                thrashing.

      BlankSub=_c
                [B]  Set the blank substitution character to
                _c.   Unquoted  spaces   in   addresses   are
                replaced  by  this  character.   Defaults to
                space (i.e., no change is made).

      CheckAliases
                [n]  Validate  the  RHS  of   aliases   when
                rebuilding the alias database.

      CheckpointInterval=_N
                [C]  Checkpoints  the queue every _N (default
                10) addresses sent.  If your system  crashes
                during  delivery  to a large list, this pre-
                vents retransmission to  any  but  the  last
                recipients.

      ClassFactor=_f_a_c_t
                [z]  The  indicated  _f_a_c_tor is multiplied by
                the message class (determined by the  Prece-
                dence:  field  in  the user header and the PP
                lines in the configuration  file)  and  sub-
                tracted  from  the priority.  Thus, messages
                with a higher  Priority:  will  be  favored.
                Defaults to 1800.

      ColonOkInAddr
                [no  short  name] If set, colons are accept-
                able    in    e-mail    addresses     (e.g.,
                "host:user").   If  not set, colons indicate
                the beginning of a RFC 822  group  construct
                ("groupname:   member1,  member2,  ...  mem-
                berN;").  Doubled colons are always  accept-
                able  ("nodename::user")  and  proper route-
                addr       nesting       is       understood
                ("<@relay:user@host>").   Furthermore,  this
                option defaults on if the configuration ver-
                sion level is less than 6 (for back compati-
                bility).  However, it must be off  for  full
                compatibility with RFC 822.










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      ConnectionCacheSize=_N
                [k]  The  maximum number of open connections
                that will be cached at a time.  The  default
                is  one.   This  delays  closing the current
                connection until either this  invocation  of
                _s_e_n_d_m_a_i_l needs to connect to another host or
                it terminates.  Setting it to zero  defaults
                to  the  old  behavior, that is, connections
                are closed immediately.  Since this consumes
                file   descriptors,   the  connection  cache
                should be kept small: 4 is probably a  prac-
                tical maximum.

      ConnectionCacheTimeout=_t_i_m_e_o_u_t
                [K] The maximum amount of time a cached con-
                nection will be permitted  to  idle  without
                activity.   If  this  time  is exceeded, the
                connection  is  immediately  closed.    This
                value  should  be small (on the order of ten
                minutes).  Before  _s_e_n_d_m_a_i_l  uses  a  cached
                connection,  it  always sends a RSET command
                to check the connection; if this  fails,  it
                reopens the connection.  This keeps your end
                from failing if the  other  end  times  out.
                The  point  of  this  option is to be a good
                network neighbor and avoid using  up  exces-
                sive   resources  on  the  other  end.   The
                default is five minutes.

      DaemonPortOptions=_o_p_t_i_o_n_s
                [O] Set server SMTP  options.   The  options
                are _k_e_y_=_v_a_l_u_e pairs.  Known keys are:

                    Port      Name/number of listening port (defaults to "smtp")
                    Addr      Address mask (defaults INADDR_ANY)
                    Family    Address family (defaults to INET)
                    Listen    Size of listen queue (defaults to 10)
                    SndBufSizeSize of TCP send buffer
                    RcvBufSizeSize of TCP receive buffer

                The _A_d_d_ress mask may be a numeric address in
                dot notation or a network name.

      DefaultCharSet=_c_h_a_r_s_e_t
                [no short name]  When  a  message  that  has
                8-bit  characters  but is not in MIME format
                is converted to MIME (see  the  EightBitMode
                option)  a character set must be included in
                the Content-Type:  header.   This  character
                set  is normally set from the Charset= field
                of the mailer descriptor.  If  that  is  not
                set,  the  value of this option is used.  If
                this  option   is   not   set,   the   value










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                "unknown-8bit" is used.

      DefaultUser=_u_s_e_r_:_g_r_o_u_p
                [u]  Set  the  default userid for mailers to
                _u_s_e_r_:_g_r_o_u_p.  If _g_r_o_u_p is omitted and _u_s_e_r is
                a  user  name  (as opposed to a numeric user
                id)  the  default  group   listed   in   the
                /etc/passwd  file  for  that user is used as
                the default group.  Both _u_s_e_r and _g_r_o_u_p  may
                be  numeric.   Mailers without the _S flag in
                the mailer definition will run as this user.
                Defaults  to  1:1.   The  value  can also be
                given as a symbolic user name.18

      DeliveryMode=_x
                [d] Deliver in mode _x.  Legal modes are:

                    i   Deliver interactively (synchronously)
                    b   Deliver in background (asynchronously)
                    q   Just queue the message (deliver during queue run)
                    d   Defer delivery and all map lookups (deliver during queue run)

                Defaults to ``b'' if no option is specified,
                ``i'' if it is specified but given no  argu-
                ment   (i.e.,   ``Od''   is   equivalent  to
                ``Odi'').  The --vv  command  line  flag  sets
                this to ii.

      DialDelay=_s_l_e_e_p_t_i_m_e
                [no  short name] Dial-on-demand network con-
                nections can see timeouts if a connection is
                opened  before  the call is set up.  If this
                is set to an interval and a connection times
                out  on the first connection being attempted
                _s_e_n_d_m_a_i_l will sleep for this amount of  time
                and try again.  This should give your system
                time to establish  the  connection  to  your
                service provider.  Units default to seconds,
                so "DialDelay=5" uses a five  second  delay.
                Defaults to zero (no retry).

      DontExpandCnames
                [no  short  name] The standards say that all
                host addresses used in a mail  message  must
                be  fully  canonical.   For example, if your
                host is named "Cruft.Foo.ORG" and  also  has
                an  alias  of "FTP.Foo.ORG", the former name
                must be used at all times.  This is enforced
____________________
   18The old gg option has been combined into the DDeeffaauullttUUsseerr
option.












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                during  host  name canonification ($[ ... $]
                lookups).  If this option is set, the proto-
                cols  are  ignored  and the "wrong" thing is
                done.  However, the IETF  is  moving  toward
                changing this standard, so the behaviour may
                become acceptable.  Please note  that  hosts
                downstream  may still rewrite the address to
                be the true canonical name however.

      DontInitGroups
                [no short name] If set, _s_e_n_d_m_a_i_l will  avoid
                using  the  initgroups(3)  call.  If you are
                running NIS, this causes a  sequential  scan
                of  the  groups.byname  map, which can cause
                your NIS server to be badly overloaded in  a
                large  domain.  The cost of this is that the
                only group found for  users  will  be  their
                primary  group  (the  one  in  the  password
                file), which will make file  access  permis-
                sions  somewhat  more  restrictive.   Has no
                effect on  systems  that  don't  have  group
                lists.

      DontPruneRoutes
                [R]  Normally,  _s_e_n_d_m_a_i_l  tries to eliminate
                any unnecessary explicit routes when sending
                an  error  message (as discussed in RFC 1123
                5.2.6).  For example, when sending an  error
                message to

                    <@known1,@known2,@known3:user@unknown>

                _s_e_n_d_m_a_i_l      will     strip     off     the
                "@known1,@known2" in order to make the route
                as  direct  as  possible.  However, if the RR
                option is set, this will  be  disabled,  and
                the  mail  will be sent to the first address
                in the route, even if  later  addresses  are
                known.  This may be useful if you are caught
                behind a firewall.

      EightBitMode=_a_c_t_i_o_n
                [8] Set handling of eight-bit  data.   There
                are   two  kinds  of  eight-bit  data:  that
                declared as  such  using  the  BBOODDYY==88BBIITTMMIIMMEE
                ESMTP  declaration or the --BB88BBIITTMMIIMMEE command
                line flag, and undeclared 8-bit  data,  that
                is,  input  that  just  happens  to be eight
                bits.  There are three basic operations that
                can  happen:  undeclared  8-bit  data can be
                automatically converted to  8BITMIME,  unde-
                clared  8-bit data can be passed as-is with-
                out conversion to MIME  (``just  send  8''),










SSMMMM::0088--6644          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


                and  declared 8-bit data can be converted to
                7-bits for transmission  to  a  non-8BITMIME
                mailer.  The possible _a_c_t_i_o_ns are:

                      s Reject undeclared 8-bit data (``strict'')
                      m Convert undeclared 8-bit data to MIME (``mime'')
                      p Pass undeclared 8-bit data (``pass'')

                In all cases properly declared 8BITMIME data
                will be converted to 7BIT as needed.

      ErrorHeader=_f_i_l_e_-_o_r_-_m_e_s_s_a_g_e
                [E] Prepend error messages  with  the  indi-
                cated  message.   If it begins with a slash,
                it is assumed to be the pathname of  a  file
                containing  a  message  (this  is the recom-
                mended setting).  Otherwise, it is a literal
                message.   The  error file might contain the
                name, email address, and/or phone number  of
                a  local postmaster who could provide assis-
                tance in to end users.   If  the  option  is
                missing or null, or if it names a file which
                does not exist or which is not readable,  no
                message is printed.

      ErrorMode=_x
                [e]  Dispose  of  errors  using mode _x.  The
                values for _x are:

                    p   Print error messages (default)
                    q   No messages, just give exit status
                    m   Mail back errors
                    w   Write back errors (mail if user not logged in)
                    e   Mail back errors and give zero exit stat always


      FallbackMXhost=_f_a_l_l_b_a_c_k_h_o_s_t
                [V] If specified, the _f_a_l_l_b_a_c_k_h_o_s_t acts like
                a  very low priority MX on every host.  This
                is intended to be used by  sites  with  poor
                network connectivity.

      ForkEachJob
                [Y]  If  set,  deliver  each job that is run
                from the queue in a separate  process.   Use
                this  option  if  you  are  short of memory,
                since the default tends to consume consider-
                able  amounts  of  memory while the queue is
                being processed.

      ForwardPath=_p_a_t_h
                [J] Set the path for  searching  for  users'
                .forward     files.     The    default    is










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                "$z/.forward".   Some  sites  that  use  the
                automounter  may  prefer  to  change this to
                "/var/forward/$u" to search a file with  the
                same name as the user in a system directory.
                It can also be set to a  sequence  of  paths
                separated  by  colons; _s_e_n_d_m_a_i_l stops at the
                first file it can  successfully  and  safely
                open.               For             example,
                "/var/forward/$u:$z/.forward"  will   search
                first  in  /var/forward/_u_s_e_r_n_a_m_e and then in
                _~_u_s_e_r_n_a_m_e/.forward (but only  if  the  first
                file does not exist).

      HelpFile=_f_i_l_e
                [H] Specify the help file for SMTP.

      HoldExpensive
                [c] If an outgoing mailer is marked as being
                expensive, don't connect immediately.   This
                requires that queueing be compiled in, since
                it will depend on a  queue  run  process  to
                actually send the mail.

      IgnoreDots
                [i]  Ignore dots in incoming messages.  This
                is always disabled (that is, dots are always
                accepted) when reading SMTP mail.

      LogLevel=_n
                [L]   Set   the  default  log  level  to  _n.
                Defaults to 9.

      M_x_v_a_l_u_e   [no long version] Set the macro _x to  _v_a_l_u_e.
                This  is intended only for use from the com-
                mand line.  The --MM flag is preferred.

      MatchGECOS
                [G] Allow fuzzy matching on the GECOS field.
                If this flag is set, and the usual user name
                lookups fail (that is,  there  is  no  alias
                with   this  name  and  a  _g_e_t_p_w_n_a_m  fails),
                sequentially search the password file for  a
                matching  entry  in  the  GECOS field.  This
                also requires that MATCHGECOS be  turned  on
                during compilation.  This option is not rec-
                ommended.

      MaxHopCount=_N
                [h] The maximum hop  count.   Messages  that
                have  been  processed  more than _N times are
                assumed to be in a loop  and  are  rejected.
                Defaults to 25.











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      MaxHostStatAge=_a_g_e
                [no  short  name] Not yet implemented.  This
                option specifies how long host status infor-
                mation  will be retained.  For example, if a
                host is found to  be  down,  connections  to
                that  host  will  not  be  retried  for this
                interval.  The units default to minutes.

      MaxQueueRunSize=_N
                [no short name] The maximum number  of  jobs
                that  will  be  processed  in a single queue
                run.  If not set, there is no limit  on  the
                size.   If  you  have very large queues or a
                very short queue run interval this could  be
                unstable.   However,  since the first _N jobs
                in queue directory  order  are  run  (rather
                than  the  _N  highest  priority  jobs)  this
                should be set as high as possible  to  avoid
                "losing"  jobs  that  happen to fall late in
                the queue directory.

      MeToo     [m] Send to me too, even if I am in an alias
                expansion.

      MaxMessageSize=_N
                [no  short name] Specify the maximum message
                size to be  advertised  in  the  ESMTP  EHLO
                response.  Messages larger than this will be
                rejected.

      MinFreeBlocks=_N
                [b] Insist on at least _N blocks free on  the
                filesystem that holds the queue files before
                accepting  email  via  SMTP.   If  there  is
                insufficient  space  _s_e_n_d_m_a_i_l  gives  a  452
                response to the MAIL command.  This  invites
                the sender to try again later.

      MinQueueAge=age
                [no  short  name]  Don't  process any queued
                jobs that have been in the queue  less  than
                the   indicated   time  interval.   This  is
                intended to allow you to get  responsiveness
                by  processing  the  queue fairly frequently
                without thrashing your system by trying jobs
                too often.  The default units are minutes.

      NoRecipientAction
                [no  short name] The action to take when you
                receive a message that has no valid  recipi-
                ent  headers  (To:,  Cc:,  Bcc:).  It can be
                NNoonnee to  pass  the  message  on  unmodified,
                which violates the protocol, AAdddd--TToo to add a










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                To: header with any recipients it  can  find
                in  the  envelope  (which  might expose Bcc:
                recipients),  AAdddd--AAppppaarreennttllyy--TToo  to  add  an
                Apparently-To:  header  (this  is  only  for
                back-compatibility and is officially  depre-
                cated),  AAdddd--TToo--UUnnddiisscclloosseedd  to add a header
                "To: undisclosed-recipients:;" to  make  the
                header legal without disclosing anything, or
                AAdddd--BBcccc to add an empty Bcc: header.

      OldStyleHeaders
                [o] Assume that the headers may  be  in  old
                format,  i.e.,  spaces  delimit names.  This
                actually turns on an adaptive algorithm:  if
                any  recipient  address  contains  a  comma,
                parenthesis, or angle bracket,  it  will  be
                assumed  that commas already exist.  If this
                flag is not on, only commas  delimit  names.
                Headers   are   always  output  with  commas
                between the names.  Defaults to off.

      OperatorChars=_c_h_a_r_l_i_s_t
                [$o macro] The list of characters  that  are
                considered to be "operators", that is, char-
                acters that delimit  tokens.   All  operator
                characters   are   tokens   by   themselves;
                sequences  of  non-operator  characters  are
                also  tokens.   White space characters sepa-
                rate tokens but are not tokens themselves --
                for example, "AAA.BBB" has three tokens, but
                "AAA BBB" has two.  If  not  set,  Operator-
                Chars defaults to ".:@[]"; additionally, the
                characters "()<>,;" are always operators.

      PostmasterCopy=_p_o_s_t_m_a_s_t_e_r
                [P] If set, copies of error messages will be
                sent  to  the  named  _p_o_s_t_m_a_s_t_e_r.   Only the
                header of the failed message is sent.  Since
                most errors are user problems, this is prob-
                ably not a good idea  on  large  sites,  and
                arguably  contains all sorts of privacy vio-
                lations, but it seems  to  be  popular  with
                certain operating systems vendors.  Defaults
                to no postmaster copies.

      PrivacyOptions=_o_p_t_,_o_p_t_,_._._.
                [p] Set the privacy _o_p_tions.  ``Privacy'' is
                really  a misnomer; many of these are just a
                way of insisting on  stricter  adherence  to
                the  SMTP  protocol.   The  _o_p_tions  can  be
                selected from:












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                    public         Allow open access
                    needmailhelo   Insist on HELO or EHLO command before MAIL
                    needexpnhelo   Insist on HELO or EHLO command before EXPN
                    noexpn         Disallow EXPN entirely
                    needvrfyhelo   Insist on HELO or EHLO command before VRFY
                    novrfy         Disallow VRFY entirely
                    restrictmailq  Restrict mailq command
                    restrictqrun   Restrict -q command line flag
                    noreceipts     Don't return success DSNs
                    goaway         Disallow essentially all SMTP status queries
                    authwarnings   Put X-Authentication-Warning: headers in messages

                The  "goaway"  pseudo-flag  sets  all  flags
                except  "restrictmailq"  and "restrictqrun".
                If mailq is restricted, only people  in  the
                same  group as the queue directory can print
                the queue.  If queue  runs  are  restricted,
                only  root and the owner of the queue direc-
                tory  can  run  the  queue.   Authentication
                Warnings  add  warnings about various condi-
                tions that may indicate  attempts  to  spoof
                the  mail  system,  such  as  using  an non-
                standard queue directory.

      QueueDirectory=_d_i_r
                [Q] Use the named _d_i_r as  the  queue  direc-
                tory.

      QueueFactor=_f_a_c_t_o_r
                [q]  Use _f_a_c_t_o_r as the multiplier in the map
                function to decide when  to  just  queue  up
                jobs  rather  than  run them.  This value is
                divided by the difference between  the  cur-
                rent load average and the load average limit
                (QQuueeuueeLLAA option) to  determine  the  maximum
                message   priority   that   will   be  sent.
                Defaults to 600000.

      QueueLA=_L_A
                [x] When the system load average exceeds _L_A,
                just queue messages (i.e., don't try to send
                them).  Defaults to 8.

      QueueSortOrder=_a_l_g_o_r_i_t_h_m
                [no short name] Sets the _a_l_g_o_r_i_t_h_m used  for
                sorting the queue.  Only the first character
                of the value  is  used.   Legal  values  are
                "host"  (to  order  by the name of the first
                host name of the first recipient) and  "pri-
                ority"  (to order strictly by message prior-
                ity).  Host ordering makes better use of the
                connection  cache,  but  may tend to process
                low priority messages that go  to  a  single










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--6699


                host  over high priority messages that go to
                several hosts; it probably shouldn't be used
                on slow network links.  Priority ordering is
                the default.

      ResolverOptions=_o_p_t_i_o_n_s
                [I] Set resolver options.  Values can be set
                using  ++_f_l_a_g  and  cleared  using --_f_l_a_g; the
                _f_l_a_gs can  be  "debug",  "aaonly",  "usevc",
                "primary",  "igntc",  "recurse", "defnames",
                "stayopen",   or   "dnsrch".    The   string
                "HasWildcardMX"  (without  a  ++ or --) can be
                specified to turn off  matching  against  MX
                records  when  doing  name  canonifications.
                NN..BB..  Prior to 8.7,  this  option  indicated
                that  the name server be responding in order
                to accept addresses.  This has been replaced
                by  checking  to  see if the "dns" method is
                listed in the service switch entry  for  the
                "hosts" service.

      SmtpGreetingMessage=_m_e_s_s_a_g_e
                [$e macro] The message printed when the SMTP
                server starts up.  Defaults to "$j  Sendmail
                $v ready at $b".

      Timeout._t_y_p_e=_t_i_m_e_o_u_t
                [r; subsumes old T option as well] Set time-
                out values.  The actual timeout is indicated
                by  the  _t_y_p_e.   The recognized timeouts and
                their default values, and their minimum val-
                ues specified in RFC 1123 section 5.3.2 are:

                    initial     wait for initial greeting message [5m, 5m]
                    helo        reply to HELO or EHLO command [5m, none]
                    mail        reply to MAIL command [10m, 5m]
                    rcpt        reply to RCPT command [1h, 5m]
                    datainit    reply to DATA command [5m, 2m]
                    datablock   data block read [1h, 3m]
                    datafinal   reply to final ``.'' in data [1h, 10m]
                    rset        reply to RSET command [5m, none]
                    quit        reply to QUIT command [2m, none]
                    misc        reply to NOOP and VERB commands [2m, none]
                    ident       IDENT protocol timeout [30s, none]
                    fileopen    timeout on opening .forward and :include: files [60s, none]
                    command     command read [1h, 5m]
                    queuereturn how long until a message is returned [5d, 5d]
                    queuewarn   how long until a warning is sent [none, none]

                All but those marked with a dagger ()  apply
                to client SMTP.  If the message is submitted
                using the  NOTIFY  SMTP  extension,  warning
                messages  will  only be sent if NOTIFY=DELAY










SSMMMM::0088--7700          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


                is specified.  The queuereturn and queuewarn
                timeouts can be further qualified with a tag
                based on the Precedence: field in  the  mes-
                sage; they must be one of "urgent" (indicat-
                ing a positive non-zero precedence) "normal"
                (indicating  a  zero  precedence),  or "non-
                urgent" (indicating  negative  precedences).
                For       example,       setting      "Time-
                out.queuewarn.urgent=1h"  sets  the  warning
                timeout  for  urgent  messages  only  to one
                hour.  The default if no precedence is indi-
                cated  is  to set the timeout for all prece-
                dences.

      RecipientFactor=_f_a_c_t
                [y] The indicated _f_a_c_tor  is  added  to  the
                priority  (thus _l_o_w_e_r_i_n_g the priority of the
                job) for each recipient,  i.e.,  this  value
                penalizes jobs with large numbers of recipi-
                ents.  Defaults to 30000.

      RefuseLA=_L_A
                [X] When the system load average exceeds _L_A,
                refuse  incoming SMTP connections.  Defaults
                to 12.

      RetryFactor=_f_a_c_t
                [Z] The _f_a_c_tor  is  added  to  the  priority
                every  time  a job is processed.  Thus, each
                time a job is processed, its  priority  will
                be  decreased  by  the  indicated value.  In
                most environments this should  be  positive,
                since  hosts that are down are all too often
                down for a long time.  Defaults to 90000.

      SaveFromLine
                [f] Save  Unix-style  "From"  lines  at  the
                front of headers.  Normally they are assumed
                redundant and discarded.

      SendMIMEErrors
                [j] If set, send error messages in MIME for-
                mat (see RFC1521 and RFC1344 for details).

      ServiceSwitchFile=_f_i_l_e_n_a_m_e
                [no  short name] If your host operating sys-
                tem has a service switch abstraction  (e.g.,
                /etc/nsswitch.conf     on     Solaris     or
                /etc/svc.conf on Ultrix and DEC OSF/1)  that
                service will be consulted and this option is
                ignored.  Otherwise, this is the name  of  a
                file  that provides the list of methods used
                to  implement  particular   services.    The










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                syntax  is  a series of lines, each of which
                is a sequence of words.  The first  word  is
                the  service  name,  and following words are
                service types.  The services  that  _s_e_n_d_m_a_i_l
                consults directly are "aliases" and "hosts."
                Service types can  be  "dns",  "nis",  "nis-
                plus",  or "files" (with the caveat that the
                appropriate  support  must  be  compiled  in
                before  the  service can be referenced).  If
                ServiceSwitchFile  is  not   specified,   it
                defaults  to  /etc/service.switch.   If that
                file does not exist, the default switch is:

                    aliases     files
                    hosts       dns nis files

                The default file is "/etc/service.switch".

      SevenBitInput
                [7] Strip input to seven bits  for  compati-
                bility  with old systems.  This shouldn't be
                necessary.

      StatusFile=_f_i_l_e
                [S] Log  summary  statistics  in  the  named
                _f_i_l_e.  If not set, no summary statistics are
                saved.  This file does not grow in size.  It
                can  be  printed using the _m_a_i_l_s_t_a_t_s(8) pro-
                gram.

      SuperSafe [s] Be super-safe when running things, i.e.,
                always  instantiate  the queue file, even if
                you are going to attempt immediate delivery.
                _S_e_n_d_m_a_i_l  always instantiates the queue file
                before returning control  the  client  under
                any   circumstances.    This  should  really
                _a_l_w_a_y_s be set.

      TempFileMode=_m_o_d_e
                [F] The file mode for queue  files.   It  is
                interpreted  in  octal by default.  Defaults
                to 0600.

      TimeZoneSpec=_t_z_i_n_f_o
                [t] Set the local time zone info  to  _t_z_i_n_f_o
                --  for  example,  "PST8PDT".   Actually, if
                this is not set, the TZ environment variable
                is  cleared (so the system default is used);
                if set but null, the user's TZ  variable  is
                used,  and  if set and non-null the TZ vari-
                able is set to this value.












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      TryNullMXList
                [w] If this system is the "best"  (that  is,
                lowest  preference) MX for a given host, its
                configuration rules should  normally  detect
                this situation and treat that condition spe-
                cially by forwarding  the  mail  to  a  UUCP
                feed,  treating  it  as  local, or whatever.
                However, in some  cases  (such  as  Internet
                firewalls)  you  may  want to try to connect
                directly to that host as though it had no MX
                records  at all.  Setting this option causes
                _s_e_n_d_m_a_i_l to try this.  The downside is  that
                errors  in  your configuration are likely to
                be diagnosed as "host unknown"  or  "message
                timed  out"  instead of something more mean-
                ingful.  This option is disrecommended.

      UnixFromLine=_f_r_o_m_l_i_n_e
                [$l macro]  Defines  the  format  used  when
                _s_e_n_d_m_a_i_l  must  add  a UNIX-style From_ line
                (that     is,     a      line      beginning
                "From<space>user").   Defaults  to  "From $g
                $d".  Don't change this unless  your  system
                uses  a  different UNIX mailbox format (very
                unlikely).

      UseErrorsTo
                [l] If there is an "Errors-To:" header, send
                error   messages  to  the  addresses  listed
                there.  They normally  go  to  the  envelope
                sender.   Use of this option causes _s_e_n_d_m_a_i_l
                to violate RFC 1123.  This option is disrec-
                ommended and deprecated.

      UserDatabaseSpec=_u_d_b_s_p_e_c
                [U] The user database specification.

      Verbose   [v]  Run  in  verbose mode.  If this is set,
                _s_e_n_d_m_a_i_l adjusts options HHoollddEExxppeennssiivvee  (old
                cc) and DDeelliivveerryyMMooddee (old dd) so that all mail
                is delivered completely in a single  job  so
                that  you  can  see the entire delivery pro-
                cess.  Option VVeerrbboossee should _n_e_v_e_r be set in
                the  configuration  file; it is intended for
                command line use only.

      All options can be specified on the command line using
      the  -O  or  -o  flag, but most will cause _s_e_n_d_m_a_i_l to
      relinquish its setuid permissions.  The  options  that
      will  not  cause this are MinFreeBlocks [b], Delivery-
      Mode [d], ErrorMode [e], IgnoreDots [i], LogLevel [L],
      MeToo  [m],  OldStyleHeaders  [o], PrivacyOptions [p],
      Timeouts   [r],   SuperSafe    [s],    Verbose    [v],










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      CheckpointInterval  [C], and SevenBitInput [7].  Also,
      M (define macro) when defining the r or  s  macros  is
      also considered "safe".

   55..77..  PP ---- PPrreecceeddeennccee DDeeffiinniittiioonnss

           Values for the "Precedence:" field may be defined
      using the PP control line.  The syntax  of  this  field
      is:

          PP_n_a_m_e==_n_u_m

      When  the  _n_a_m_e is found in a "Precedence:" field, the
      message class is set  to  _n_u_m.   Higher  numbers  mean
      higher  precedence.   Numbers  less than zero have the
      special property that if an error occurs  during  pro-
      cessing  the body of the message will not be returned;
      this is expected to be used for "bulk"  mail  such  as
      through  mailing  lists.   The  default  precedence is
      zero.  For example, our list of precedences is:

          Pfirst-class=0
          Pspecial-delivery=100
          Plist=-30
          Pbulk=-60
          Pjunk=-100

      People writing mailing list exploders  are  encouraged
      to use "Precedence: list".  Older versions of _s_e_n_d_m_a_i_l
      (which discarded all error returns for negative prece-
      dences)  didn't  recognize  this  name,  giving  it  a
      default precedence of zero.  This  allows  list  main-
      tainers  to see error returns on both old and new ver-
      sions of _s_e_n_d_m_a_i_l.

   55..88..  VV ---- CCoonnffiigguurraattiioonn VVeerrssiioonn LLeevveell

           To provide compatibility with  old  configuration
      files,  the  VV line has been added to define some very
      basic semantics of the configuration file.  These  are
      not  intended  to  be long term supports; rather, they
      describe compatibility features which will probably be
      removed in future releases.

           NN..BB..::  these  version  _l_e_v_e_l_s  have nothing to do
      with the version _n_u_m_b_e_r on the files.  For example, as
      of  this writing version 8 config files (specifically,
      8.7) used version level 6 configurations.

           "Old" configuration files are defined as  version
      level one.  Version level two files make the following
      changes:











SSMMMM::0088--7744          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


       (1)   Host name canonification ($[ ... $]) appends  a
             dot  if  the name is recognized; this gives the
             config file a way of finding  out  if  anything
             matched.   (Actually, this just initializes the
             "host" map with the  "-a."   flag  --  you  can
             reset  it  to  anything you prefer by declaring
             the map explicitly.)

       (2)   Default  host  name  extension  is   consistent
             throughout  processing;  version level one con-
             figurations turned off domain  extension  (that
             is,  adding  the local domain name) during cer-
             tain points in processing.  Version  level  two
             configurations are expected to include a trail-
             ing dot to indicate that the  name  is  already
             canonical.

       (3)   Local  names  that  are  not aliases are passed
             through a new distinguished ruleset five;  this
             can  be  used  to  append  a local relay.  This
             behaviour can be  prevented  by  resolving  the
             local name with an initial `@'.  That is, some-
             thing that resolves to a  local  mailer  and  a
             user  name  of  "vikki"  will be passed through
             ruleset five, but a user name of "@vikki"  will
             have  the  `@'  stripped,  will  not  be passed
             through ruleset five,  but  will  otherwise  be
             treated  the  same  as  the prior example.  The
             expectation is  that  this  might  be  used  to
             implement  a  policy where mail sent to "vikki"
             was handled by a central hub, but mail sent  to
             "vikki@localhost" was delivered directly.

           Version  level three files allow # initiated com-
      ments on all lines.  Exceptions are backslash  escaped
      # marks and the $# syntax.

           Version  level four configurations are completely
      equivalent to level three for historical reasons.

           Version level five configuration files change the
      default  definition  of $$ww to be just the first compo-
      nent of the hostname.

           Version level six configuration files change many
      of  the local processing options (such as aliasing and
      matching the beginning of the address for `|'  charac-
      ters)  to  be  mailer  flags; this allows fine-grained
      control over the special local processing.  Level  six
      configuration  files  may  also use long option names.
      The CCoolloonnOOkkIInnAAddddrr  option  (to  allow  colons  in  the
      local-part  of  addresses)  defaults oonn for lower num-
      bered  configuration  files;  the  configuration  file










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--7755


      requires some additional intelligence to properly han-
      dle the RFC 822 group construct.

           The VV line may have an optional //_v_e_n_d_o_r to  indi-
      cate  that  this configuration file uses modifications
      specific  to  a  particular  vendor19.   You  may  use
      "/Berkeley" to emphasize that this configuration  file
      uses the Berkeley dialect of _s_e_n_d_m_a_i_l.

   55..99..  KK ---- KKeeyy FFiillee DDeeccllaarraattiioonn

           Special maps can be defined using the line:

          Kmapname mapclass arguments

      The  _m_a_p_n_a_m_e is the handle by which this map is refer-
      enced in the rewriting rules.   The  _m_a_p_c_l_a_s_s  is  the
      name  of a type of map; these are compiled in to _s_e_n_d_-
      _m_a_i_l.  The _a_r_g_u_m_e_n_t_s are interpreted depending on  the
      class;  typically,  there  would  be a single argument
      naming the file containing the map.

           Maps are referenced using the syntax:

          $( _m_a_p _k_e_y $@ _a_r_g_u_m_e_n_t_s $: _d_e_f_a_u_l_t $)

      where either or both of the _a_r_g_u_m_e_n_t_s or _d_e_f_a_u_l_t  por-
      tion may be omitted.  The _$_@ _a_r_g_u_m_e_n_t_s may appear more
      than once.  The indicated _k_e_y and _a_r_g_u_m_e_n_t_s are passed
      to  the appropriate mapping function.  If it returns a
      value, it replaces the input.  If it does not return a
      value  and  the  _d_e_f_a_u_l_t  is  specified,  the  _d_e_f_a_u_l_t
      replaces  the  input.    Otherwise,   the   input   is
      unchanged.

           During  replacement  of  either  a  map  value or
      default the string  "%_n"  (where  _n  is  a  digit)  is
      replaced by the corresponding _a_r_g_u_m_e_n_t.  Argument zero
      is always the database key.  For example, the rule

          R$- ! $+       $: $(uucp $1 $@ $2 $: %1 @ %0 . UUCP $)

      Looks up the UUCP name in a (user defined)  UUCP  map;
      if  not  found  it  turns  it  into ".UUCP" form.  The
      database might contain records like:

____________________
   19And of course, vendors are encouraged to add themselves
to  the  list  of  recognized vendors by editing the routine
_s_e_t_v_e_n_d_o_r  in  _c_o_n_f_._c.   Please   send   e-mail   to   send-
[e-mail] to register your vendor dialect.












SSMMMM::0088--7766          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


          decvax         %1@%0.DEC.COM
          research       %1@%0.ATT.COM


           The built in map with both name and class  "host"
      is  the  host name canonicalization lookup.  Thus, the
      syntax:

          $(host _h_o_s_t_n_a_m_e$)

      is equivalent to:

          $[_h_o_s_t_n_a_m_e$]


           There are many defined classes.

      dbm       Database lookups using the ndbm(3)  library.
                _S_e_n_d_m_a_i_l  must be compiled with DDBBMM defined.

      btree     Database lookups using the  btree  interface
                to  the  Berkeley  db(3)  library.  _S_e_n_d_m_a_i_l
                must be compiled with NNEEWWDDBB defined.

      hash      Database lookups using the hash interface to
                the  Berkeley  db(3) library.  _S_e_n_d_m_a_i_l must
                be compiled with NNEEWWDDBB defined.

      nis       NIS lookups.  _S_e_n_d_m_a_i_l must be compiled with
                NNIISS defined.

      nisplus   NIS+  lookups.   _S_e_n_d_m_a_i_l  must  be compiled
                with NNIISSPPLLUUSS defined.  The argument  is  the
                name  of  the  table to use for lookups, and
                the --kk and --vv flags may be used to  set  the
                key and value columns respectively.

      hesiod    Hesiod  lookups.   _S_e_n_d_m_a_i_l must be compiled
                with HHEESSIIOODD defined.

      netinfo   NeXT NetInfo lookups.  _S_e_n_d_m_a_i_l must be com-
                piled with NNEETTIINNFFOO defined.

      text      Text  file  lookups.  The format of the text
                file is defined by the --kk  (key  field  num-
                ber), --vv (value field number), and --zz (field
                delimiter) flags.

      stab      Internal symbol table lookups.  Used  inter-
                nally for aliasing.

      implicit  Really  should  be called "alias" -- this is
                used to get the default  lookups  for  alias










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--7777


                files,  and  is  the  default if no class is
                specified for alias files.

      user      Looks up users using  _g_e_t_p_w_n_a_m(3).   The  --vv
                flag  can be used to specify the name of the
                field to return (although this  is  normally
                used only to check the existence of a user).

      host      Canonifies host domain names.  Given a  host
                name  it  calls  the name server to find the
                canonical name for that host.

      sequence  The arguments on the `K' line are a list  of
                maps;  the  resulting map searches the argu-
                ment maps in order until it  finds  a  match
                for  the indicated key.  For example, if the
                key definition is:

                    Kmap1 ...
                    Kmap2 ...
                    Kseqmap sequence map1 map2

                then a lookup against "seqmap" first does  a
                lookup  in  map1.   If  that  is  found,  it
                returns immediately.   Otherwise,  the  same
                key is used for map2.

      switch    Much like the "sequence" map except that the
                order of maps is determined by  the  service
                switch.   The  argument  is  the name of the
                service to be looked up; the values from the
                service  switch  are appended to the service
                name to create new map names.  For  example,
                consider the key definition:

                    Kali switch aliases

                together with the service switch entry:

                    aliases        nis files

                This causes a query against the map "ali" to
                search   maps   named   "aliases.nis"    and
                "aliases.files" in that order.

      dequote   Strip  double  quotes  (")  from a name.  It
                does not strip  backslashes,  and  will  not
                strip  quotes  if the resulting string would
                contain unscannable syntax (that  is,  basic
                errors  like unbalanced angle brackets; more
                sophisticated errors such as  unknown  hosts
                are  not  checked).   The  intent is for use
                when trying to accept mail from systems such










SSMMMM::0088--7788          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


                as  DECnet  that  routinely quote odd syntax
                such as

                    "49ers::ubell"

                A typical usage is probably something like:

                    Kdequote dequote

                    ...

                    R$-            $: $(dequote $1 $)
                    R$- $+         $: $>3 $1 $2

                Care must be  taken  to  prevent  unexpected
                results; for example,

                    "|someprogram < input > output"

                will have quotes stripped, but the result is
                probably not what you had in  mind.   Fortu-
                nately these cases are rare.

           Most  of  these  accept  as  arguments  the  same
      optional flags and a filename (or a mapname  for  NIS;
      the filename is the root of the database path, so that
      ".db" or some  other  extension  appropriate  for  the
      database type will be added to get the actual database
      name).  Known flags are:

      -o        Indicates that this map is optional --  that
                is, if it cannot be opened, no error is pro-
                duced, and _s_e_n_d_m_a_i_l will behave  as  if  the
                map existed but was empty.

      -N,  -O    If neither --NN or --OO are specified, _s_e_n_d_m_a_i_l
                uses an adaptive algorithm to decide whether
                or  not to look for null bytes on the end of
                keys.  It starts by trying both; if it finds
                any  key  with  a  null  byte it never tries
                again without a null byte  and  vice  versa.
                If  --NN is specified it never tries without a
                null byte and if --OO is  specified  it  never
                tries  with  a  null  byte.   Setting one of
                these can speed matches but are never neces-
                sary.   If  both  --NN  and  --OO are specified,
                _s_e_n_d_m_a_i_l will never try any matches  at  all
                --  that is, everything will appear to fail.

      -a_x       Append the string _x on  successful  matches.
                For  example, the default _h_o_s_t map appends a
                dot on successful matches.











SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--7799


      -f        Do not fold upper to lower case before look-
                ing up the key.

      -m        Match  only  (without  replacing the value).
                If you only care about the  existence  of  a
                key  and  not  the  value (as you might when
                searching the  NIS  map  "hosts.byname"  for
                example),  this  flag  prevents the map from
                substituting the  value.   However,  The  -a
                argument  is  still appended on a match, and
                the default is  still  taken  if  the  match
                fails.

      -k_k_e_y_c_o_l  The  key  column  name  (for NIS+) or number
                (for text lookups).

      -v_v_a_l_c_o_l  The value column name (for NIS+)  or  number
                (for text lookups).

      -z_d_e_l_i_m   The column delimiter (for text lookups).  It
                can be a single character or one of the spe-
                cial  strings  "\n" or "\t" to indicate new-
                line  or  tab  respectively.    If   omitted
                entirely,   the   column  separator  is  any
                sequence of whitespace.

      -s_s_p_a_c_e_s_u_b
                For the dequote map only, the  character  to
                use to replace space characters after a suc-
                cessful dequote.

           The _d_b_m map appends the strings ".pag" and ".dir"
      to  the  given  filename; the two _d_b-based maps append
      ".db".  For example, the map specification

          Kuucp dbm -o -N /usr/lib/uucpmap

      specifies an optional map named "uucp" of class "dbm";
      it  always  has null bytes at the end of every string,
      and the data is located in /usr/lib/uucpmap.{dir,pag}.

           The  program  _m_a_k_e_m_a_p(8) can be used to build any
      of the three database-oriented  maps.   It  takes  the
      following flags:

      -f        Do  not fold upper to lower case in the map.

      -N        Include null bytes in keys.

      -o        Append to an existing (old) file.

      -r        Allow replacement  of  existing  keys;  nor-
                mally,  re-inserting  an  existing key is an










SSMMMM::0088--8800          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


                error.

      -v        Print what is happening.

      The _s_e_n_d_m_a_i_l daemon does not have to be  restarted  to
      read the new maps as long as you change them in place;
      file locking is used so that the maps  won't  be  read
      while they are being updated.20

           New classes can be added in the routine sseettuuppmmaappss
      in file ccoonnff..cc.

   55..1100..  TThhee UUsseerr DDaattaabbaassee

           If you have a version of _s_e_n_d_m_a_i_l with  the  user
      database  package  compiled in, the handling of sender
      and recipient addresses is modified.

           The location of this database is controlled  with
      the UUsseerrDDaattaabbaasseeSSppeecc option.

      55..1100..11..  SSttrruuccttuurree ooff tthhee uusseerr ddaattaabbaassee

              The  database is a sorted (BTree-based) struc-
         ture.  User records are stored with the key:

             _u_s_e_r_-_n_a_m_e::_f_i_e_l_d_-_n_a_m_e

         The  sorted  database  format  ensures  that   user
         records  are  clustered together.  Meta-information
         is always stored with a leading colon.

              Field names define both the syntax and  seman-
         tics of the value.  Defined fields include:

         maildrop  The   delivery  address  for  this  user.
                   There may  be  multiple  values  of  this
                   record.   In  particular,  mailing  lists
                   will have one _m_a_i_l_d_r_o_p  record  for  each
                   user on the list.

         mailname  The outgoing mailname for this user.  For
                   each outgoing name, there  should  be  an
                   appropriate _m_a_i_l_d_r_o_p record for that name
                   to   allow   return   mail.    See   also
                   _:_d_e_f_a_u_l_t_:_m_a_i_l_n_a_m_e.

____________________
   20That  is,  don't  create new maps and then use _m_v(1) to
move them into place.  Since the maps are already  open  the
new maps will never be seen.












SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--8811


         mailsender
                   Changes  any mail sent to this address to
                   have the indicated envelope sender.  This
                   is  intended  for mailing lists, and will
                   normally be the name  of  an  appropriate
                   -request  address.  It is very similar to
                   the owner-_l_i_s_t syntax in the alias  file.

         fullname  The full name of the user.

         office-address
                   The office address for this user.

         office-phone
                   The office phone number for this user.

         office-fax
                   The office FAX number for this user.

         home-address
                   The home address for this user.

         home-phone
                   The home phone number for this user.

         home-fax  The home FAX number for this user.

         project   A (short) description of the project this
                   person is affiliated with.  In  the  Uni-
                   versity  this  is  often just the name of
                   their graduate advisor.

         plan      A pointer  to  a  file  from  which  plan
                   information can be gathered.

              As of this writing, only a few of these fields
         are actually being used by _s_e_n_d_m_a_i_l:  _m_a_i_l_d_r_o_p  and
         _m_a_i_l_n_a_m_e.   A  _f_i_n_g_e_r  program  that uses the other
         fields is planned.

      55..1100..22..  UUsseerr ddaattaabbaassee sseemmaannttiiccss

              When the rewriting rules submit an address  to
         the  local  mailer, the user name is passed through
         the alias file.  If no alias is found  (or  if  the
         alias  points  back  to the same address), the name
         (with ":maildrop" appended) is then used as  a  key
         in  the  user  database.  If no match occurs (or if
         the maildrop points at the same address),  forward-
         ing is tried.

              If  the  first token of the user name returned
         by ruleset 0 is an  "@"  sign,  the  user  database










SSMMMM::0088--8822          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


         lookup  is  skipped.   The  intent is that the user
         database will act as a set of defaults for a  clus-
         ter  (in  our case, the Computer Science Division);
         mail sent to a specific machine should ignore these
         defaults.

              When  mail  is  sent,  the name of the sending
         user is looked up in the database.   If  that  user
         has  a  "mailname" record, the value of that record
         is used as their outgoing  name.   For  example,  I
         might have a record:

             eric:mailname  [e-mail]

         This  would  cause  my  outgoing mail to be sent as
         Eric.Allman.

              If a "maildrop" is found for the user, but  no
         corresponding  "mailname" record exists, the record
         ":default:mailname" is consulted.  If present, this
         is  the  name of a host to override the local host.
         For example,  in  our  case  we  would  set  it  to
         "CS.Berkeley.EDU".  The effect is that anyone known
         in the database gets their outgoing mail stamped as
         "[e-mail]",  but  people  not listed in
         the database use the local hostname.

      55..1100..33..  CCrreeaattiinngg tthhee ddaattaabbaassee2211

              The user database is built from  a  text  file
         using  the  _m_a_k_e_m_a_p utility (in the distribution in
         the makemap subdirectory).   The  text  file  is  a
         series  of  lines  corresponding to userdb records;
         each line has a key and a value separated by  white
         space.   The  key is always in the format described
         above -- for example:

             eric:maildrop

         This file is normally installed in a system  direc-
         tory;  for example, it might be called _/_e_t_c_/_u_s_e_r_d_b.
         To make the database version of the  map,  run  the
         program:

             makemap btree /etc/userdb.db < /etc/userdb

         Then  create  a  config  file  that uses this.  For
____________________
   21These instructions are known to be incomplete.   A  fu-
ture  version  of  the  user  database  is planned including
things such as finger service -- and good documentation.












SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--8833


         example, using the V8 M4 configuration, include the
         following line in your .mc file:

             define(`confUSERDB_SPEC', /etc/userdb.db)


66..  OOTTHHEERR CCOONNFFIIGGUURRAATTIIOONN

        There  are  some  configuration  changes that can be
   made by recompiling  _s_e_n_d_m_a_i_l.   This  section  describes
   what  changes  can be made and what has to be modified to
   make them.  In most  cases  this  should  be  unnecessary
   unless you are porting _s_e_n_d_m_a_i_l to a new environment.

   66..11..  PPaarraammeetteerrss iinn ssrrcc//MMaakkeeffiillee

           These  parameters  are  intended  to describe the
      compilation environment, not site policy,  and  should
      normally be defined in src/Makefile.

      NDBM      If  set,  the new version of the DBM library
                that allows multiple databases will be used.
                If  neither  NDBM  nor NEWDB are set, a much
                less efficient method  of  alias  lookup  is
                used.

      NEWDB     If  set,  use  the new database package from
                Berkeley (from  4.4BSD).   This  package  is
                substantially  faster  than DBM or NDBM.  If
                NEWDB and NDBM are both set,  _s_e_n_d_m_a_i_l  will
                read  DBM  files,  but  will  create and use
                NEWDB files.

      NIS       Include support for NIS.   If  set  together
                with _b_o_t_h NEWDB and NDBM, _s_e_n_d_m_a_i_l will cre-
                ate both DBM and NEWDB files if and only  if
                an  alias file includes the substring "/yp/"
                in the name.  This is intended for  compati-
                bility  with  Sun Microsystems' _m_k_a_l_i_a_s pro-
                gram used on YP masters.

      NISPLUS   Compile in support for NIS+.

      NETINFO   Compile in support for  NetInfo  (NeXT  sta-
                tions).

      HESIOD    Compile in support for Hesiod.

      _PATH_SENDMAILCF
                The pathname of the sendmail.cf file.

      _PATH_SENDMAILPID
                The pathname of the sendmail.pid file.










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           There are also several compilation flags to indi-
      cate the environment such as "_AIX3" and "_SCO_unix_".
      See  the  READ_ME  file  for the latest scoop on these
      flags.

   66..22..  PPaarraammeetteerrss iinn ssrrcc//ccoonnff..hh

           Parameters and compilation options are defined in
      conf.h.   Most  of these need not normally be tweaked;
      common parameters are all  in  sendmail.cf.   However,
      the  sizes  of  certain  primitive  vectors, etc., are
      included in this  file.   The  numbers  following  the
      parameters are their default value.

           This  document is not the best source of informa-
      tion  for  compilation  flags   in   conf.h   --   see
      src/READ_ME or src/conf.h itself.

      MAXLINE [2048]
                  The maximum line length of any input line.
                  If message lines exceed this  length  they
                  will  still  be  processed correctly; how-
                  ever,  header  lines,  configuration  file
                  lines,  alias lines, etc., must fit within
                  this limit.

      MAXNAME [256]
                  The maximum length of any name, such as  a
                  host or a user name.

      MAXPV  [40]  The  maximum  number of parameters to any
                  mailer.  This limits the number of recipi-
                  ents  that  may  be passed in one transac-
                  tion.  It can be set to any arbitrary num-
                  ber  above  about  10, since _s_e_n_d_m_a_i_l will
                  break up a delivery into  smaller  batches
                  as  needed.   A  higher  number may reduce
                  load on your system, however.

      MAXATOM [100]
                  The maximum number of atoms (tokens) in  a
                  single  address.  For example, the address
                  "[e-mail]" is seven atoms.

      MAXMAILERS [25]
                  The maximum number of mailers that may  be
                  defined in the configuration file.

      MAXRWSETS [200]
                  The  maximum number of rewriting sets that
                  may be defined.  The first half  of  these
                  are  reserved  for  numeric  specification
                  (e.g., ``S92''), while the upper half  are










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--8855


                  reserved    for    auto-numbering   (e.g.,
                  ``Sfoo'').  Thus, with a value of  200  an
                  attempt  to  use ``S99'' will succeed, but
                  ``S100'' will fail.

      MAXPRIORITIES [25]
                  The  maximum  number  of  values  for  the
                  "Precedence:"  field  that  may be defined
                  (using the PP line in sendmail.cf).

      MAXUSERENVIRON [100]
                  The maximum number of items  in  the  user
                  environment  that will be passed to subor-
                  dinate mailers.

      MAXMXHOSTS [20]
                  The maximum number of MX records  we  will
                  accept for any single host.

      MAXALIASDB [12]
                  The maximum number of alias databases that
                  can be open at any time.  Note that  there
                  may also be an open file limit.

      MAXMAPSTACK [12]
                  The  maximum  number  of  maps that may be
                  "stacked" in a sseeqquueennccee class map.

      MAXMIMEARGS [20]
                  The maximum number of arguments in a  MIME
                  Content-Type: header; additional arguments
                  will be ignored.

      MAXMIMENESTING [20]
                  The maximum depth to which  MIME  messages
                  may  be nested (that is, nested Message or
                  Multipart documents; this does  not  limit
                  the  number of components in a single Mul-
                  tipart document).

      A number of other compilation  options  exist.   These
      specify  whether  or  not specific code should be com-
      piled in.  Ones marked with are 0/1 valued.

      NETINET     If set, support for Internet protocol net-
                  working is compiled in.  Previous versions
                  of _s_e_n_d_m_a_i_l referred to  this  as  DAEMON;
                  this old usage is now incorrect.  Defaults
                  on; turn it off in the  Makefile  if  your
                  system doesn't support the Internet proto-
                  cols.












SSMMMM::0088--8866          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      NETISO      If set, support for ISO protocol  network-
                  ing  is compiled in (it may be appropriate
                  to #define this in the Makefile instead of
                  conf.h).

      LOG         If  set, the _s_y_s_l_o_g routine in use at some
                  sites is used.   This  makes  an  informa-
                  tional  log  record  for each message pro-
                  cessed, and makes a  higher  priority  log
                  record   for   internal   system   errors.
                  SSTTRROONNGGLLYY RREECCOOMMMMEENNDDEEDD --  if  you  want  no
                  logging,  turn it off in the configuration
                  file.

      MATCHGECOS  Compile in the code to do  ``fuzzy  match-
                  ing''  on  the GECOS field in /etc/passwd.
                  This also  requires  that  the  MMaattcchhGGEECCOOSS
                  option be turned on.

      NAMED_BIND  Compile in code to use the Berkeley Inter-
                  net Name Domain (BIND) server  to  resolve
                  TCP/IP host names.

      NOTUNIX     If  you  are using a non-UNIX mail format,
                  you can set this flag to turn off  special
                  processing of UNIX-style "From " lines.

      QUEUE       This  flag should be set to compile in the
                  queueing code.  If this is not set,  mail-
                  ers must accept the mail immediately or it
                  will be returned to the sender.

      SMTP        If set, the code to handle user and server
                  SMTP  will  be  compiled in.  This is only
                  necessary if your machine has some  mailer
                  that speaks SMTP (this means most machines
                  everywhere).

      USERDB      Include  the  eexxppeerriimmeennttaall  Berkeley  user
                  information database package.  This adds a
                  new level of local name expansion  between
                  aliasing and forwarding.  It also uses the
                  NEWDB package.  This may change in  future
                  releases.

      The  following  options are normally turned on in per-
      operating-system clauses in conf.h.

      IDENTPROTO  Compile in the IDENT protocol  as  defined
                  in  RFC  1413.   This  defaults on for all
                  systems except  Ultrix,  which  apparently
                  has the interesting "feature" that when it
                  receives a "host unreachable"  message  it










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--8877


                  closes  all open connections to that host.
                  Since some  firewall  gateways  send  this
                  error code when you access an unauthorized
                  port (such as 113, used by IDENT),  Ultrix
                  cannot receive email from such hosts.

      SYSTEM5     Set  all  of  the  compilation  parameters
                  appropriate for System V.

      HASFLOCK    Use Berkeley-style fflloocckk instead of System
                  V  lloocckkff  to  do file locking.  Due to the
                  highly unusual semantics of  locks  across
                  forks in lloocckkff, this should always be used
                  if at all possible.

      HASINITGROUPS
                  Set this if  your  system  has  the  _i_n_i_t_-
                  _g_r_o_u_p_s_(_)  call (if you have multiple group
                  support).  This is the default if  SYSTEM5
                  is _n_o_t defined or if you are on HPUX.

      HASUNAME    Set  this  if you have the _u_n_a_m_e(2) system
                  call (or corresponding  library  routine).
                  Set by default if SYSTEM5 is set.

      HASGETDTABLESIZE
                  Set  this if you have the _g_e_t_d_t_a_b_l_e_s_i_z_e(2)
                  system call.

      HASWAITPID  Set this if  you  have  the  _h_a_s_w_a_i_t_p_i_d(2)
                  system call.

      SFS_TYPE    The mechanism that can be used to get file
                  system capacity information.   The  values
                  can  be one of SFS_USTAT (use the ustat(2)
                  syscall), SFS_4ARGS (use the four argument
                  statfs(2)  syscall),  SFS_VFS (use the two
                  argument   statfs(2)   syscall   including
                  <sys/vfs.h>), SFS_MOUNT (use the two argu-
                  ment    statfs(2)    syscall     including
                  <sys/mount.h>),  SFS_STATFS  (use  the two
                  argument   statfs(2)   syscall   including
                  <sys/statfs.h>),  SFS_STATVFS (use the two
                  argument   statfs(2)   syscall   including
                  <sys/statvfs.h>),  or  SFS_NONE (no way to
                  get this information).

      LA_TYPE     The  load  average  type.    Details   are
                  described below.

      The  are  several  built-in ways of computing the load
      average.  _S_e_n_d_m_a_i_l tries to auto-configure them  based
      on  imperfect guesses; you can select one using the _c_c










SSMMMM::0088--8888          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      option --DDLLAA__TTYYPPEE==_t_y_p_e, where _t_y_p_e is:

      LA_INT      The kernel stores the load average in  the
                  kernel  as an array of long integers.  The
                  actual  values  are  scaled  by  a  factor
                  FSCALE (default 256).

      LA_SHORT    The  kernel stores the load average in the
                  kernel as an array of short integers.  The
                  actual  values  are  scaled  by  a  factor
                  FSCALE (default 256).

      LA_FLOAT    The kernel stores the load average in  the
                  kernel  as  an  array  of double precision
                  floats.

      LA_MACH     Use MACH-style load averages.

      LA_SUBR     Call the _g_e_t_l_o_a_d_a_v_g  routine  to  get  the
                  load average as an array of doubles.

      LA_ZERO     Always  return  zero  as the load average.
                  This is the fallback case.

      If type LA_INT, LA_SHORT, or  LA_FLOAT  is  specified,
      you  may  also need to specify _PATH_UNIX (the path to
      your system binary) and LA_AVENRUN (the  name  of  the
      variable  containing  the  load average in the kernel;
      usually "_avenrun" or "avenrun").

   66..33..  CCoonnffiigguurraattiioonn iinn ssrrcc//ccoonnff..cc

           The following changes can be made in conf.c.

      66..33..11..  BBuuiilltt--iinn HHeeaaddeerr SSeemmaannttiiccss

              Not all header semantics are  defined  in  the
         configuration  file.  Header lines that should only
         be included by certain mailers (as  well  as  other
         more  obscure  semantics)  must be specified in the
         _H_d_r_I_n_f_o table in _c_o_n_f_._c.  This table  contains  the
         header name (which should be in all lower case) and
         a set of header control  flags  (described  below),
         The flags are:

         H_ACHECK    Normally  when the check is made to see
                     if a header line is compatible  with  a
                     mailer,  _s_e_n_d_m_a_i_l  will  not  delete an
                     existing line.  If this  flag  is  set,
                     _s_e_n_d_m_a_i_l   will  delete  even  existing
                     header lines.  That is, if this bit  is
                     set  and  the mailer does not have flag
                     bits  set  that  intersect   with   the










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--8899


                     required  mailer  flags  in  the header
                     definition in sendmail.cf,  the  header
                     line is _a_l_w_a_y_s deleted.

         H_EOH       If  this  header field is set, treat it
                     like a blank line, i.e., it will signal
                     the end of the header and the beginning
                     of the message text.

         H_FORCE     Add  this  header  entry  even  if  one
                     existed  in  the  message before.  If a
                     header entry does  not  have  this  bit
                     set,  _s_e_n_d_m_a_i_l  will  not  add  another
                     header line if a header  line  of  this
                     name  already existed.  This would nor-
                     mally be used to stamp the  message  by
                     everyone who handled it.

         H_TRACE     If  set,  this  is  a timestamp (trace)
                     field.  If the number of  trace  fields
                     in  a  message  exceeds a preset amount
                     the message is returned on the  assump-
                     tion that it has an aliasing loop.

         H_RCPT      If  set,  this field contains recipient
                     addresses.  This is used by the --tt flag
                     to  determine who to send to when it is
                     collecting recipients from the message.

         H_FROM      This  flag  indicates  that  this field
                     specifies a sender.  The order of these
                     fields  in  the _H_d_r_I_n_f_o table specifies
                     _s_e_n_d_m_a_i_l's preference for  which  field
                     to return error messages to.

         H_ERRORSTO  Addresses in this header should receive
                     error messages.

         H_CTE       This  header  is  a   Content-Transfer-
                     Encoding header.

         H_CTYPE     This header is a Content-Type header.

         H_STRIPVAL  Strip  the  value  from the header (for
                     Bcc:).

         Let's look at a sample _H_d_r_I_n_f_o specification:
















SSMMMM::0088--9900          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


             struct hdrinfo                    HdrInfo[] =
             {
                      /* originator fields, most to least significant  */
                 "resent-sender",              H_FROM,
                 "resent-from",                H_FROM,
                 "sender",                     H_FROM,
                 "from",                       H_FROM,
                 "full-name",                  H_ACHECK,
                 "errors-to",                  H_FROM|H_ERRORSTO,
                      /* destination fields */
                 "to",                         H_RCPT,
                 "resent-to",                  H_RCPT,
                 "cc",                         H_RCPT,
                 "bcc",                        H_RCPT|H_STRIPVAL,
                      /* message identification and control */
                 "message",                    H_EOH,
                 "text",                       H_EOH,
                      /* trace fields */
                 "received",                   H_TRACE|H_FORCE,
                      /* miscellaneous fields */
                 "content-transfer-encoding",  H_CTE,
                 "content-type",               H_CTYPE,

                 NULL,                         0,
             };

         This structure indicates that the  "To:",  "Resent-
         To:",   and  "Cc:"  fields  all  specify  recipient
         addresses.  Any "Full-Name:" field will be  deleted
         unless  the  required mailer flag (indicated in the
         configuration file) is specified.   The  "Message:"
         and "Text:" fields will terminate the header; these
         are used by random dissenters  around  the  network
         world.  The "Received:" field will always be added,
         and can be used to trace messages.

              There are a number of important  points  here.
         First,  header  fields  are not added automatically
         just because they are  in  the  _H_d_r_I_n_f_o  structure;
         they must be specified in the configuration file in
         order to be  added  to  the  message.   Any  header
         fields  mentioned in the configuration file but not
         mentioned in the  _H_d_r_I_n_f_o  structure  have  default
         processing  performed;  that  is,  they  are  added
         unless they were in the message  already.   Second,
         the  _H_d_r_I_n_f_o  structure only specifies cliched pro-
         cessing; certain headers are processed specially by
         ad  hoc  code regardless of the status specified in
         _H_d_r_I_n_f_o.  For example, the  "Sender:"  and  "From:"
         fields are always scanned on ARPANET mail to deter-













SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--9911


         mine the sender22; this  is  used  to  perform  the
         "return  to  sender"  function.   The  "From:"  and
         "Full-Name:" fields are used to determine the  full
         name  of  the sender if possible; this is stored in
         the macro $$xx and used in a number of ways.

      66..33..22..  RReessttrriiccttiinngg UUssee ooff EEmmaaiill

              If it is necessary to restrict mail through  a
         relay,  the  _c_h_e_c_k_c_o_m_p_a_t  routine  can be modified.
         This routine is called for every recipient address.
         It  returns an exit status indicating the status of
         the message.  The status EX_OK accepts the address,
         EX_TEMPFAIL queues the message for a later try, and
         other values (commonly EX_UNAVAILABLE)  reject  the
         message.  It is up to _c_h_e_c_k_c_o_m_p_a_t to print an error
         message (using _u_s_r_e_r_r) if the message is  rejected.
         For example, _c_h_e_c_k_c_o_m_p_a_t could read:

             int
             checkcompat(to, e)
                 register ADDRESS *to;
                 register ENVELOPE *e;
             {
                 register STAB *s;

                 s = stab("private", ST_MAILER, ST_FIND);
                 if (s != NULL && e->e_from.q_mailer != LocalMailer &&
                     to->q_mailer == s->s_mailer)
                 {
                     usrerr("No private net mail allowed through this machine");
                     return (EX_UNAVAILABLE);
                 }
                 if (MsgSize > 50000 && bitnset(M_LOCALMAILER, to->q_mailer))
                 {
                     usrerr("Message too large for non-local delivery");
                     e->e_flags |= EF_NORETURN;
                     return (EX_UNAVAILABLE);
                 }
                 return (EX_OK);
             }

         This would reject messages greater than 50000 bytes
         unless they were local.  The _E_F___N_O_R_E_T_U_R_N  flag  can
         be  set in _e_-_>_e___f_l_a_g_s to suppress the return of the
         actual body of the message  in  the  error  return.
         The  actual use of this routine is highly dependent
         on the implementation, and use should be limited.
____________________
   22Actually, this is no longer true in SMTP; this informa-
tion is contained in the envelope.  The older ARPANET proto-
cols did not completely distinguish envelope from header.











SSMMMM::0088--9922          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      66..33..33..  LLooaadd AAvveerraaggee CCoommppuuttaattiioonn

              The routine _g_e_t_l_a should return an  approxima-
         tion of the current system load average as an inte-
         ger.  There are several versions included on compi-
         lation flags as described above.

      66..33..44..  NNeeww DDaattaabbaassee MMaapp CCllaasssseess

              New  key maps can be added by creating a class
         initialization  function  and  a  lookup  function.
         These are then added to the routine _s_e_t_u_p_m_a_p_s_.

              The initialization function is called as

             _x_x_x_map_init(MAP *map, char *mapname, char *args)

         The _m_a_p is an internal data structure.  The _m_a_p_n_a_m_e
         is the name of the map (used for  error  messages).
         The _a_r_g_s is a pointer to the rest of the configura-
         tion  file  line;  flags  and  filenames   can   be
         extracted from this line.  The initialization func-
         tion must return TRUE if it successfully opened the
         map, FALSE otherwise.

              The lookup function is called as

             _x_x_x_map_lookup(MAP *map, char buf[], int bufsize, char **av, int *statp)

         The _m_a_p defines the map internally.  The parameters
         _b_u_f and _b_u_f_s_i_z_e have the input key.   This  may  be
         (and  often  is)  used  destructively.  The _a_v is a
         list of arguments passed in from the rewrite  line.
         The  lookup function should return a pointer to the
         new value.  IF the map lookup fails, _*_s_t_a_t_p  should
         be  set  to  an exit status code; in particular, it
         should be set to EX_TEMPFAIL if recovery is  to  be
         attempted by the higher level code.

      66..33..55..  QQuueeuueeiinngg FFuunnccttiioonn

              The routine _s_h_o_u_l_d_q_u_e_u_e is called to decide if
         a message should be  queued  or  processed  immedi-
         ately.   Typically this compares the message prior-
         ity to the current load average.  The default defi-
         nition is:

















SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--9933


             bool
             shouldqueue(pri, ctime)
                 long pri;
                 time_t ctime;
             {
                 if (CurrentLA < QueueLA)
                     return (FALSE);
                 return (pri > (QueueFactor / (CurrentLA - QueueLA + 1)));
             }

         If  the  current load average (global variable _C_u_r_-
         _r_e_n_t_L_A,  which  is  set  before  this  function  is
         called) is less than the low threshold load average
         (option xx, variable _Q_u_e_u_e_L_A),  _s_h_o_u_l_d_q_u_e_u_e  returns
         FALSE  immediately  (that is, it should _n_o_t queue).
         If  the  current  load  average  exceeds  the  high
         threshold   load   average   (option   XX,  variable
         _R_e_f_u_s_e_L_A), _s_h_o_u_l_d_q_u_e_u_e  returns  TRUE  immediately.
         Otherwise,  it  computes  the function based on the
         message  priority,  the  queue  factor  (option  qq,
         global  variable  _Q_u_e_u_e_F_a_c_t_o_r), and the current and
         threshold load averages.

              An implementation wishing to take  the  actual
         age  of  the  message into account can also use the
         _c_t_i_m_e parameter, which is the time that the message
         was first submitted to _s_e_n_d_m_a_i_l.  Note that the _p_r_i
         parameter is already  weighted  by  the  number  of
         times  the  message  has  been tried (although this
         tends to lower the priority  of  the  message  with
         time);  the  expectation is that the _c_t_i_m_e would be
         used as an "escape clause" to ensure that  messages
         are eventually processed.

      66..33..66..  RReeffuussiinngg IInnccoommiinngg SSMMTTPP CCoonnnneeccttiioonnss

              The function _r_e_f_u_s_e_c_o_n_n_e_c_t_i_o_n_s returns TRUE if
         incoming SMTP connections should be  refused.   The
         current  implementation is based exclusively on the
         current load average and the  refuse  load  average
         option (option XX, global variable _R_e_f_u_s_e_L_A):

             bool
             refuseconnections()
             {
                 return (CurrentLA >= RefuseLA);
             }

         A  more  clever  implementation  could look at more
         system resources.













SSMMMM::0088--9944          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      66..33..77..  LLooaadd AAvveerraaggee CCoommppuuttaattiioonn

              The routine _g_e_t_l_a  returns  the  current  load
         average  (as  a rounded integer).  The distribution
         includes several possible implementations.  If  you
         are  porting  to  a new environment you may need to
         add some new tweaks.23

   66..44..  CCoonnffiigguurraattiioonn iinn ssrrcc//ddaaeemmoonn..cc

           The  file  _s_r_c_/_d_a_e_m_o_n_._c contains a number of rou-
      tines that are dependent on the local networking envi-
      ronment.   The  version  supplied assumes you have BSD
      style sockets.

           In previous releases,  we  recommended  that  you
      modify the routine _m_a_p_h_o_s_t_n_a_m_e if you wanted to gener-
      alize $$[[ ... $$]] lookups.  We now  recommend  that  you
      create a new keyed map instead.

77..  CCHHAANNGGEESS IINN VVEERRSSIIOONN 88

        The following summarizes changes since the last com-
   monly  available  version  of  _s_e_n_d_m_a_i_l  (5.67).   For  a
   detailed list, consult the file RELEASE_NOTES in the root
   directory of the _s_e_n_d_m_a_i_l distribution.

   77..11..  CCoonnnneeccttiioonn CCaacchhiinngg

           Instead of closing SMTP connections  immediately,
      those  connections are cached for possible future use.
      The advent of MX records made this effective for mail-
      ing   lists;   in  addition,  substantial  performance
      improvements can be expected for queue processing.

   77..22..  MMXX PPiiggggyybbaacckkiinngg

           If two hosts with different  names  in  a  single
      message  happen to have the same set of MX hosts, they
      can be  sent  in  the  same  transaction.   Version  8
      notices this and tries to batch the messages.

   77..33..  RRFFCC 11112233 CCoommpplliiaannccee

           A  number of changes have been made to make _s_e_n_d_-
      _m_a_i_l "conditionally compliant" (that is, _s_e_n_d_m_a_i_l sat-
      isfies  all of the "MUST" clauses and most but not all
      of the "SHOULD" clauses in RFC 1123).
____________________
   23If   you   do,   please   send   updates    to    send-
[e-mail].












SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--9955


           The major areas of change are  (numbers  are  RFC
      1123 section numbers):

      5.2.7    Response to RCPT command is fast.

      5.2.8    Numeric  IP addresses are logged in Received:
               lines.

      5.2.17   Self domain literal is properly handled.

      5.3.2    Better control over individual timeouts.

      5.3.3    Error messages are sent as "From:<>".

      5.3.3    Error messages are never sent to "<>".

      5.3.3    Route-addrs are pruned.

      The areas in which _s_e_n_d_m_a_i_l  is  not  "unconditionally
      compliant" are:

      5.2.6    _S_e_n_d_m_a_i_l does do header munging.

      5.2.10   _S_e_n_d_m_a_i_l  doesn't  always  use the exact SMTP
               message text as listed in RFC 821.

      5.3.1.1  _S_e_n_d_m_a_i_l doesn't guarantee only  one  connect
               for each host in queue runs.

      5.3.1.1  _S_e_n_d_m_a_i_l doesn't always provide adequate con-
               currency limits.

   77..44..  EExxtteennddeedd SSMMTTPP SSuuppppoorrtt

           Version 8 includes  both  sending  and  receiving
      support  for  Extended  SMTP support as defined by RFC
      1651 (basic) and RFC 1653 (SIZE); and limited  support
      for RFC 1652 (BODY).

   77..55..  EEiigghhtt--BBiitt CClleeaann

           Previous  versions  of _s_e_n_d_m_a_i_l used the 0200 bit
      for quoting.  This version avoids that use.   However,
      for compatibility with RFC 822, you can set option `7'
      to get seven bit stripping.

           Individual mailers can still  produce  seven  bit
      output using the `7' mailer flag.

   77..66..  UUsseerr DDaattaabbaassee

           The  user  database  is  an  as-yet  experimental
      attempt to provide unified  large-site  name  support.










SSMMMM::0088--9966          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


      We  are installing it at Berkeley; future versions may
      show significant modifications.

   77..77..  IImmpprroovveedd BBIINNDD SSuuppppoorrtt

           The BIND support, particularly  for  MX  records,
      had  a  number  of annoying "features" which have been
      removed in this release.  In  particular,  these  more
      tightly  bind  (pun intended) the name server to _s_e_n_d_-
      _m_a_i_l, so that the name  server  resolution  rules  are
      incorporated directly into sseennddmmaaiill.

   77..88..  KKeeyyeedd FFiilleess

           Generalized keyed files is an idea taken directly
      from IDA _s_e_n_d_m_a_i_l (albeit with a completely  different
      implementation).  They can be useful on large sites.

           Version 8 also understands YP.

   77..99..  MMuullttii--WWoorrdd CCllaasssseess

           Classes can now be multiple words.  For example,

          CShofmann.CS.Berkeley.EDU

      allows   you   to   match   the  entire  string  "hof-
      mann.CS.Berkeley.EDU"  using  the   single   construct
      "$=S".

   77..1100..  DDeeffeerrrreedd MMaaccrroo EExxppaannssiioonn

           The $$&&_x construct has been adopted from IDA.

   77..1111..  IIDDEENNTT PPrroottooccooll SSuuppppoorrtt

           The IDENT protocol as defined in RFC 1413 is sup-
      ported.

   77..1122..  PPaarrssiinngg BBuugg FFiixxeess

           A number of small bugs having to do  with  things
      like  backslash-escaped quotes inside of comments have
      been fixed.

   77..1133..  SSeeppaarraattee EEnnvveellooppee//HHeeaaddeerr PPrroocceessssiinngg

           Since the From: line is passed in separately from
      the  envelope  sender, these have both been made visi-
      ble; the $$gg macro is set to the envelope sender during
      processing  of  mailer argument vectors and the header
      sender during processing of headers.











SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--9977


           It is also  possible  to  specify  separate  per-
      mailer  envelope  and  header processing.  The SSender-
      RWSet and RRecipientRWset arguments for mailers can  be
      specified as _e_n_v_e_l_o_p_e_/_h_e_a_d_e_r to give different rewrit-
      ings for envelope versus header addresses.

   77..1144..  OOwwnneerr--LLiisstt PPrrooppaaggaatteess ttoo EEnnvveellooppee

           When an alias has an associated owner-list  name,
      that  alias  is  used  to  change  the envelope sender
      address.  This will  cause  downstream  errors  to  be
      returned to that owner.

   77..1155..  DDyynnaammiicc HHeeaaddeerr AAllllooccaattiioonn

           The  fixed  size  limit  on header lines has been
      eliminated.

   77..1166..  NNeeww CCoommmmaanndd LLiinnee FFllaaggss

           The --BB flag has been added to pass in  body  type
      information.

           The  --pp  flag  has been added to pass in protocol
      information.

           The --XX flag has been added to  allow  logging  of
      all protocol in and out of _s_e_n_d_m_a_i_l for debugging.

           The --OO flag simplies setting long-form options.

   77..1177..  EEnnhhaanncceedd CCoommmmaanndd LLiinnee FFllaaggss

           The  --qq  flag can limit limit a queue run to spe-
      cific recipients, senders, or queue ids using  --qqRR_s_u_b_-
      _s_t_r_i_n_g,, --qqSS_s_u_b_s_t_r_i_n_g,, oorr --qqII_s_u_b_s_t_r_i_n_g rreessppeeccttiivveellyy..

   77..1188..  NNeeww aanndd OOlldd CCoonnffiigguurraattiioonn LLiinnee TTyyppeess

           The  KK  line  has  been added to declare database
      maps.

           The VV line has been added to declare the configu-
      ration version level.

           The  MM line has a "D=" field that lets you change
      into a temporary directory while that mailer  is  run-
      ning.   It  also  has a "U=" field to allow you to set
      the user and group id to  be  used  when  running  the
      mailer.













SSMMMM::0088--9988          SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


   77..1199..  NNeeww OOppttiioonnss

           Several new options have been added, many to sup-
      port new features, others to  allow  tuning  that  was
      previously  available  only  by recompiling.  They are
      described in detail in Section 5.1.5.  Briefly,

      b    Insist on a minimum number of disk blocks.

      C    Set checkpoint interval.

      E    Default error message.

      G    Enable GECOS matching.

      h    Maximum hop count.

      j    Send errors in MIME-encapsulated format.

      J    Forward file path.

      k    Connection cache size

      K    Connection cache lifetime.

      l    Enable Errors-To: header.  These headers  violate
           RFC 1123; this option is included to provide back
           compatibility with old versions of _s_e_n_d_m_a_i_l.

      O    Set incoming SMTP  daemon  options,  such  as  an
           alternate SMTP port.

      p    Privacy options.

      R    Don't prune route-addrs.

      U    User database spec.

      V    Fallback "MX" host.

      w    "Best MX" handling technique.

      7    Do not run eight bit clean.

      8    Eight bit data handling mode.

   77..2200..  EExxtteennddeedd OOppttiioonnss

           The  rr (read timeout), II (use BIND), and TT (queue
      timeout) options have been extended to  pass  in  more
      information.












SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee          SSMMMM::0088--9999


   77..2211..  NNeeww MMaaiilleerr FFllaaggss

           Several new mailer flags have been added.

      a    Try  to use ESMTP when creating a connection.  If
           this is not set, _s_e_n_d_m_a_i_l will still try  if  the
           other  end hints that it knows about ESMTP in its
           greeting message; this flag says to try  even  if
           it  doesn't  hint.   If the EHLO (extended hello)
           command fails, _s_e_n_d_m_a_i_l falls back to old SMTP.

      A    Try the user part of addresses for this mailer as
           aliases.

      b    Ensure  that  there is a blank line at the end of
           all messages.

      c    Strip all comments from  addresses;  this  should
           only  be  used as a last resort when dealing with
           cranky mailers.

      g    Never use the null sender as the envelope sender,
           even  when  running SMTP.  Although this violates
           RFC 1123, it may be necessary when you must  deal
           with some obnoxious old hosts.

      k    Turn off the loopback check in the HELO protocol;
           doing this may cause mailer loops.

      o    Always run the mailer as  the  recipient  of  the
           message.

      w    This user should have a passwd file entry.

      5    Try ruleset 5 if no local aliases.

      7    Strip all output to 7 bits.

      :    Check for :include: files.

      |    Check for |program addresses.

      /    Check for /file addresses.

      @    Check this user against the user database.

   77..2222..  LLoonngg OOppttiioonn NNaammeess

           All  options  can  be specified using long names,
      and some new options can only be specified  with  long
      names.












SSMMMM::0088--110000         SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


   77..2233..  NNeeww PPrree--DDeeffiinneedd MMaaccrrooss

           The following macros are pre-defined:

      $k   The UUCP node name, nominally from _u_n_a_m_e(2) call.

      $m   The domain part of our full hostname.

      $_   The RFC 1413-provided sender address.

   77..2244..  NNeeww LLHHSS TTookkeenn

           Version 8 allows $$@@ on the Left Hand Side  of  an
      "R" line to match zero tokens.  This is intended to be
      used to match the null input.

   77..2255..  BBiiggggeerr DDeeffaauullttss

           Version 8 allows up to 100  rulesets  instead  of
      30.   It  is recommended that rulesets 0-9 be reserved
      for _s_e_n_d_m_a_i_l's dedicated use in future releases.

           The total number of MX records that can  be  used
      has been raised to 20.

           The number of queued messages that can be handled
      at one time has been raised from 600 to 1000.

   77..2266..  DDiiffffeerreenntt DDeeffaauulltt TTuunniinngg PPaarraammeetteerrss

           Version 8 has changed the default parameters  for
      tuning  queue  costs  to make the number of recipients
      more important than the size of the message (for small
      messages).   This  is  reasonable if you are connected
      with reasonably fast links.

   77..2277..  AAuuttoo--QQuuoottiinngg iinn AAddddrreesssseess

           Previously, the "Full Name <email address>"  syn-
      tax  would generate incorrect protocol output if "Full
      Name" had special characters such as dot.   This  ver-
      sion puts quotes around such names.

   77..2288..  SSyymmbboolliicc NNaammeess OOnn EErrrroorr MMaaiilleerr

           Several  names  have been built in to the $@ por-
      tion of the $#error mailer.

   77..2299..  SSMMTTPP VVRRFFYY DDooeessnn''tt EExxppaanndd

           Previous versions of _s_e_n_d_m_a_i_l  treated  VRFY  and
      EXPN  the  same.  In this version, VRFY doesn't expand
      aliases or follow .forward files.  EXPN still does.










SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee         SSMMMM::0088--110011


           As an optimization, if you run with your  default
      delivery   mode   being   queue-only   or  deliver-in-
      background, the  RCPT  command  will  also  not  chase
      aliases  and  .forward files.  It will chase them when
      it processes the queue.

   77..3300..  [[IIPPCC]] MMaaiilleerrss AAllllooww MMuullttiippllee HHoossttss

           When an address resolves to  a  mailer  that  has
      "[IPC]"  as its "Path", the $@ part (host name) can be
      a colon-separated list of hosts instead  of  a  single
      hostname.   This  asks _s_e_n_d_m_a_i_l to search the list for
      the first entry that is available exactly as though it
      were  an  MX  record.  The intent is to route internal
      traffic through internal networks  without  publishing
      an  MX  record to the net.  MX expansion is still done
      on the individual items.

   77..3311..  AAlliiaasseess EExxtteennddeedd

           The implementation has  been  merged  with  maps.
      Among other things, this supports NIS-based aliases.

   77..3322..  PPoorrttaabbiilliittyy aanndd SSeeccuurriittyy EEnnhhaanncceemmeennttss

           A  number  of  internal changes have been made to
      enhance portability.

           Several fixes have  been  made  to  increase  the
      paranoia factor.

   77..3333..  MMiisscceellllaanneeoouuss CChhaannggeess

           _S_e_n_d_m_a_i_l writes a _/_e_t_c_/_s_e_n_d_m_a_i_l_._p_i_d file with the
      current process id of the SMTP daemon.

           Two people using the same program in their  .for-
      ward  file  are considered different so that duplicate
      elimination doesn't delete one of them.

           The _m_a_i_l_s_t_a_t_s program  prints  mailer  names  and
      gets   the  location  of  the  _s_e_n_d_m_a_i_l_._s_t  file  from
      _/_e_t_c_/_s_e_n_d_m_a_i_l_._c_f.

           Many minor bugs have been fixed, such as handling
      of backslashes inside of quotes.

           A  hook  (ruleset  5)  has  been  added  to allow
      rewriting of local addresses after aliasing.














SSMMMM::0088--110022         SSeennddmmaaiill IInnssttaallllaattiioonn aanndd OOppeerraattiioonn GGuuiiddee


88..  AACCKKNNOOWWLLEEDDGGEEMMEENNTTSS

        I've worked on _s_e_n_d_m_a_i_l for  many  years,  and  many
   employers  have  been remarkably patient about letting me
   work on a large project that was not part of my  official
   job.   This includes time on the INGRES Project at Berke-
   ley, at Britton Lee, and again on the Mammoth Project  at
   Berkeley.

        Much  of  the  second wave of improvements should be
   credited to Bryan Costales of  ICSI.   As  he  passed  me
   drafts  of  his  book on _s_e_n_d_m_a_i_l I was inspired to start
   working on things again.  Bryan  was  also  available  to
   bounce ideas off of.

        Many,  many  people  contributed  chunks of code and
   ideas to _s_e_n_d_m_a_i_l.  It has proven to be a  group  network
   effort.   Version  8  in  particular was a group project.
   The following people made notable contributions:

       John Beck, Hewlett-Packard
       Keith Bostic, CSRG, University of California, Berkeley
       Andrew Cheng, Sun Microsystems
       Michael J. Corrigan, University of California, San Diego
       Bryan Costales, International Computer Science Institute
       Pa..r (Pell) Emanuelsson
       Craig Everhart, Transarc Corporation
       Tom Ivar Helbekkmo, Norwegian School of Economics
       Allan E. Johannesen, WPI
       Jonathan Kamens, OpenVision Technologies, Inc.
       Takahiro Kanbe, Fuji Xerox Information Systems Co., Ltd.
       Brian Kantor, University of California, San Diego
       Murray S. Kucherawy, HookUp Communication Corp.
       Bruce Lilly, Sony U.S.
       Karl London
       Motonori Nakamura, Ritsumeikan University & Kyoto University
       John Gardiner Myers, Carnegie Mellon University
       Neil Rickert, Northern Illinois University
       Eric Schnoebelen, Convex Computer Corp.
       Eric Wassenaar, National Institute for Nuclear and High Energy Physics, Amsterdam
       Christophe Wolfhugel, Pasteur Institute & Herve Schauer Consultants (Paris)

   I apologize for anyone I have omitted, misspelled, misat-
   tributed,  or otherwise missed.  At this point, I suspect
   that at least a hundred people have contributed code, and
   many  more  have contributed ideas, comments, and encour-
   agement.  I've tried to list them in the RELEASE_NOTES in
   the distribution directory.  I appreciate their contribu-
   tion as well.

        Special thanks are reserved for Michael Corrigan and
   Christophe  Wolfhugel, who besides being wonderful guinea
   pigs and contributors have also consented to be added  to










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   the  ``[e-mail]''  list and, by answering
   the bulk of the questions sent to that list,  have  freed
   me up to do other work.































































                          AAPPPPEENNDDIIXX  AA


                      CCOOMMMMAANNDD LLIINNEE FFLLAAGGSS




     Arguments   must   be   presented   with  flags  before
addresses.  The flags are:

-b_x       Set operation mode to _x.  Operation modes are:

              m   Deliver mail (default)
              s   Speak SMTP on input side
              a   ``Arpanet'' mode (get envelope sender information from header)
              d   Run as a daemon
              t   Run in test mode
              v   Just verify addresses, don't collect or deliver
              i   Initialize the alias database
              p   Print the mail queue


-B_t_y_p_e    Indicate body type.

-C_f_i_l_e    Use a different configuration file.  _S_e_n_d_m_a_i_l runs
          as  the invoking user (rather than root) when this
          flag is specified.

-d_l_e_v_e_l   Set debugging level.

-f _a_d_d_r   The sender's machine address is _a_d_d_r.

-F_n_a_m_e    Sets the full name of this user to _n_a_m_e.

-h _c_n_t    Sets the "hop count" to _c_n_t.  This represents  the
          number of times this message has been processed by
          _s_e_n_d_m_a_i_l (to the extent that it  is  supported  by
          the underlying networks).  _C_n_t is incremented dur-
          ing processing, and if  it  reaches  MAXHOP  (cur-
          rently  30)  _s_e_n_d_m_a_i_l throws away the message with
          an error.

-n        Don't do aliasing or forwarding.

-r _a_d_d_r   An obsolete form of --ff.

-o_x_v_a_l_u_e  Set  option  _x  to  the  specified  _v_a_l_u_e.   These
          options are described in Appendix B.
____________________
   Deprecated.




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-O_o_p_t_i_o_n==_v_a_l_u_e
          Set  _o_p_t_i_o_n  to the specified _v_a_l_u_e (for long form
          option names).

-M_x_v_a_l_u_e  _S_e_t _m_a_c_r_o _x _t_o _t_h_e _s_p_e_c_i_f_i_e_d _v_a_l_u_e_.

-p_p_r_o_t_o_c_o_l
          Set the sending protocol.  Programs are encouraged
          to  set  this.   The  protocol field can be in the
          form _p_r_o_t_o_c_o_l::_h_o_s_t to set both the sending  proto-
          col and sending host.  For example, "-pUUCP:uunet"
          sets the sending protocol to UUCP and the  sending
          host to uunet.  (Some existing programs use -oM to
          set the r and s  macros;  this  is  equivalent  to
          using -p.)

-q_t_i_m_e    Try to process the queued up mail.  If the time is
          given, a _s_e_n_d_m_a_i_l will run through  the  queue  at
          the  specified  interval  to  deliver queued mail;
          otherwise, it only runs once.

-q_X_s_t_r_i_n_g Run the queue once, limiting  the  jobs  to  those
          matching  _X_s_t_r_i_n_g.   The  key letter _X can be II to
          limit based on queue identifier, RR to limit  based
          on  recipient,  or  SS to limit based on sender.  A
          particular queued job is accepted if  one  of  the
          corresponding  addresses  contains  the  indicated
          _s_t_r_i_n_g.

-t        Read the  header  for  "To:",  "Cc:",  and  "Bcc:"
          lines, and send to everyone listed in those lists.
          The "Bcc:" line will be  deleted  before  sending.
          Any  addresses  in  the  argument  vector  will be
          deleted from the send list.

-X _l_o_g_f_i_l_e
          Log all traffic in and  out  of  _s_e_n_d_m_a_i_l  in  the
          indicated  _l_o_g_f_i_l_e  for debugging mailer problems.
          This produces a  lot  of  data  very  quickly  and
          should be used sparingly.

     There  are a number of options that may be specified as
primitive flags.  These are the e,  i,  m,  and  v  options.
Also, the f option may be specified as the --ss flag.






















                        AAPPPPEENNDDIIXX  BB


                     QQUUEEUUEE FFIILLEE FFOORRMMAATTSS




     This  appendix describes the format of the queue files.
These files live in the directory defined by the QQ option in
the   _s_e_n_d_m_a_i_l_._c_f   file,   usually   _/_v_a_r_/_s_p_o_o_l_/_m_q_u_e_u_e   or
_/_u_s_r_/_s_p_o_o_l_/_m_q_u_e_u_e.

     All queue files have the name _xff_A_A_A_9_9_9_9_9 where _A_A_A_9_9_9_9_9
is  the  _i_d for this message and the _x is a type.  The first
letter of the id encodes the hour of the day that  the  mes-
sage  was  received  by  the  system  (with A being the hour
between midnight and 1:00AM).  All files with  the  same  id
collectively define one message.

     The types are:

d    The data file.  The message body (excluding the header)
     is kept in this file.

q    The queue control file.  This file contains the  infor-
     mation necessary to process the job.

t    A  temporary  file.   These are an image of the qqff file
     when it is being rebuilt.  It should be renamed to a qqff
     file very quickly.

x    A  transcript  file, existing during the life of a ses-
     sion showing everything that happens during  that  ses-
     sion.

     The  qqff  file  is  structured as a series of lines each
beginning with a code letter.  The lines are as follows:

V    The version number of the queue file  format,  used  to
     allow new _s_e_n_d_m_a_i_l binaries to read queue files created
     by older versions.  Defaults to version zero.  Must  be
     the first line of the file if present.

H    A  header definition.  There may be any number of these
     lines.  The order  is  important:  they  represent  the
     order  in the final message.  These use the same syntax
     as header definitions in the configuration file.

C    The    controlling    address.     The    syntax     is
     "localuser:aliasname".   Recipient  addresses following
     this line will be flagged so that  deliveries  will  be
     run  as the _l_o_c_a_l_u_s_e_r (a user name from the /etc/passwd


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     file); _a_l_i_a_s_n_a_m_e is the name of the alias that expanded
     to this address (used for printing messages).

Q    The  ``original  recipient'',  specified  by the ORCPT=
     field in an ESMTP transaction.   Used  exclusively  for
     Delivery  Status Notifications.  It applies only to the
     immediately following `R' line.

R    A recipient address.  This will normally be  completely
     aliased, but is actually realiased when the job is pro-
     cessed.  There will be one  line  for  each  recipient.
     Version  1  qf  files  also  include  a  leading colon-
     terminated list of flags, which can be `S' to return  a
     message  on  successful final delivery, `F' to return a
     message on failure, `D' to return a message if the mes-
     sage  is  delayed, `B' to indicate that the body should
     be returned, `N' to suppress returning  the  body,  and
     `P'  to  declare this as a ``primary'' (command line or
     SMTP-session) address.

S    The sender address.  There may only  be  one  of  these
     lines.

T    The job creation time.  This is used to compute when to
     time out the job.

P    The current message priority.  This is  used  to  order
     the  queue.  Higher numbers mean lower priorities.  The
     priority changes as the message sits in the queue.  The
     initial  priority  depends on the message class and the
     size of the message.

M    A message.  This line is printed by the _m_a_i_l_q  command,
     and  is generally used to store status information.  It
     can contain any text.

F    Flag bits, represented as one letter per flag.  Defined
     flag bits are rr indicating that this is a response mes-
     sage and ww indicating that a warning message  has  been
     sent announcing that the mail has been delayed.

N    The total number of delivery attempts.

K    The time (as seconds since January 1, 1970) of the last
     delivery attempt.

I    The i-number of the data file;  this  can  be  used  to
     recover  your mail queue after a disastrous disk crash.

$    A macro definition.  The values of certain  macros  (as
     of  this writing, only $$rr and $$ss) are passed through to
     the queue run phase.











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B    The body type.  The remainder of the  line  is  a  text
     string  defining the body type.  If this field is miss-
     ing, the body type is assumed to be "undefined" and  no
     special  processing  is  attempted.   Legal  values are
     "7BIT" and "8BITMIME".

O    The original MTS value (from  the  ESMTP  transaction).
     For Deliver Status Notifications only.

Z    The  original envelope id (from the ESMTP transaction).
     For Deliver Status Notifications only.

     As an example, the following is a queue  file  sent  to
"[e-mail]"                              and
"[e-mail]"1:

    P835771
    T404261372
    Seric
    Ceric:[e-mail]
    [e-mail]
    [e-mail]
    H?P?return-path: <[e-mail]>
    Hreceived: by vangogh.CS.Berkeley.EDU (5.108/2.7) id AAA06703;
        Fri, 17 Jul 92 00:28:55 -0700
    Hreceived: from mail.CS.Berkeley.EDU by vangogh.CS.Berkeley.EDU (5.108/2.7)
        id AAA06698; Fri, 17 Jul 92 00:28:54 -0700
    Hreceived: from [128.32.31.21] by mail.CS.Berkeley.EDU (5.96/2.5)
        id AA22777; Fri, 17 Jul 92 03:29:14 -0400
    Hreceived: by foo.bar.baz.de (5.57/Ultrix3.0-C)
        id AA22757; Fri, 17 Jul 92 09:31:25 GMT
    H?F?from: [e-mail] (Eric Allman)
    H?x?full-name: Eric Allman
    Hmessage-id: <[e-mail]>
    HTo: [e-mail]
    Hsubject: this is an example message

This shows the person who sent the message,  the  submission
time  (in seconds since January 1, 1970), the message prior-
ity, the message class, the recipients, and the headers  for
the message.






____________________
   1This example is contrived and  probably  inaccurate  for
your  environment.   Glance  over it to get an idea; nothing
can replace looking at what your own system generates.















                        AAPPPPEENNDDIIXX  CC


                  SSUUMMMMAARRYY OOFF SSUUPPPPOORRTT FFIILLEESS




     This  is  a  summary of the support files that _s_e_n_d_m_a_i_l
creates or generates.  Many of these can be changed by edit-
ing  the  sendmail.cf  file;  check there to find the actual
pathnames.

/usr/sbin/sendmail
          The binary of _s_e_n_d_m_a_i_l.

/usr/bin/newaliases
          A link to  /usr/sbin/sendmail;  causes  the  alias
          database  to  be rebuilt.  Running this program is
          completely equivalent to giving _s_e_n_d_m_a_i_l  the  --bbii
          flag.

/usr/bin/mailq
          Prints  a listing of the mail queue.  This program
          is equivalent to using the --bbpp flag to _s_e_n_d_m_a_i_l.

/etc/sendmail.cf
          The configuration file, in textual form.

/usr/lib/sendmail.hf
          The SMTP help file.

/etc/sendmail.st
          A statistics file; need not be present.

/etc/sendmail.pid
          Created in daemon mode; it contains the process id
          of  the  current  SMTP daemon.  If you use this in
          scripts; use ``head -1'' to  get  just  the  first
          line;  later versions of _s_e_n_d_m_a_i_l may add informa-
          tion to subsequent lines.

/etc/aliases
          The textual version of the alias file.

/etc/aliases.{pag,dir}
          The alias file in _d_b_m(3) format.

/var/spool/mqueue
          The directory in which the mail queue  and  tempo-
          rary files reside.




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/var/spool/mqueue/qf*
          Control (queue) files for messages.

/var/spool/mqueue/df*
          Data files.

/var/spool/mqueue/tf*
          Temporary  versions  of  the qf files, used during
          queue file rebuild.

/var/spool/mqueue/xf*
          A transcript of the current session.



















































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          replace it with a blank sheet for double-sided output.












































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                          TABLE OF CONTENTS

1.  BASIC INSTALLATION ................................    7
   1.1.  Compiling Sendmail ...........................    7
      1.1.1.  Tweaking the Makefile ...................    7
      1.1.2.  Compilation and installation ............    8
   1.2.  Configuration Files ..........................    9
   1.3.  Details of Installation Files ................   11
      1.3.1.  /usr/sbin/sendmail ......................   11
      1.3.2.  /etc/sendmail.cf ........................   12
      1.3.3.  /usr/bin/newaliases .....................   12
      1.3.4.  /var/spool/mqueue .......................   12
      1.3.5.  /etc/aliases* ...........................   12
      1.3.6.  /etc/rc .................................   13
      1.3.7.  /usr/lib/sendmail.hf ....................   15
      1.3.8.  /etc/sendmail.st ........................   15
      1.3.9.  /usr/bin/mailq ..........................   15
2.  NORMAL OPERATIONS .................................   15
   2.1.  The System Log ...............................   15
      2.1.1.  Format ..................................   15
      2.1.2.  Levels ..................................   17
   2.2.  Dumping State ................................   17
   2.3.  The Mail Queue ...............................   17
      2.3.1.  Printing the queue ......................   18
      2.3.2.  Forcing the queue .......................   18
   2.4.  The Service Switch ...........................   19
   2.5.  The Alias Database ...........................   20
      2.5.1.  Rebuilding the alias database ...........   21
      2.5.2.  Potential problems ......................   22
      2.5.3.  List owners .............................   22
   2.6.  User Information Database ....................   23
   2.7.  Per-User Forwarding (.forward Files) .........   23
   2.8.  Special Header Lines .........................   23
      2.8.1.  Errors-To: ..............................   24
      2.8.2.  Apparently-To: ..........................   24
      2.8.3.  Precedence ..............................   24
   2.9.  IDENT Protocol Support .......................   24
3.  ARGUMENTS .........................................   25
   3.1.  Queue Interval ...............................   26
   3.2.  Daemon Mode ..................................   26
   3.3.  Forcing the Queue ............................   26
   3.4.  Debugging ....................................   27
   3.5.  Changing the Values of Options ...............   27
   3.6.  Trying a Different Configuration File ........   28
   3.7.  Logging Traffic ..............................   28
   3.8.  Testing Configuration Files ..................   28
4.  TUNING ............................................   30
   4.1.  Timeouts .....................................   30
      4.1.1.  Queue interval ..........................   30
      4.1.2.  Read timeouts ...........................   30
      4.1.3.  Message timeouts ........................   32
   4.2.  Forking During Queue Runs ....................   33
   4.3.  Queue Priorities .............................   33










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   4.4.  Load Limiting ................................   34
   4.5.  Delivery Mode ................................   35
   4.6.  Log Level ....................................   35
   4.7.  File Modes ...................................   36
      4.7.1.  To suid or not to suid?  ................   36
      4.7.2.  Should my alias database be  writable?
         ..............................................   37
   4.8.  Connection Caching ...........................   37
   4.9.  Name Server Access ...........................   38
   4.10.  Moving the Per-User Forward Files ...........   39
   4.11.  Free Space ..................................   40
   4.12.  Maximum Message Size ........................   40
   4.13.  Privacy Flags ...............................   40
   4.14.  Send to Me Too ..............................   41
5.  THE WHOLE SCOOP ON THE CONFIGURATION FILE .........   41
   5.1.  R and S -- Rewriting Rules ...................   41
      5.1.1.  The left hand side ......................   42
      5.1.2.  The right hand side .....................   43
      5.1.3.  Semantics of rewriting rule sets ........   45
      5.1.4.  IPC mailers .............................   46
   5.2.  D -- Define Macro ............................   47
   5.3.  C and F -- Define Classes ....................   51
   5.4.  M -- Define Mailer ...........................   53
   5.5.  H -- Define Header ...........................   58
   5.6.  O -- Set Option ..............................   59
   5.7.  P -- Precedence Definitions ..................   73
   5.8.  V -- Configuration Version Level .............   73
   5.9.  K -- Key File Declaration ....................   75
   5.10.  The User Database ...........................   80
      5.10.1.  Structure of the user database .........   80
      5.10.2.  User database semantics ................   81
      5.10.3.  Creating the database21 ................   82
6.  OTHER CONFIGURATION ...............................   83
   6.1.  Parameters in src/Makefile ...................   83
   6.2.  Parameters in src/conf.h .....................   84
   6.3.  Configuration in src/conf.c ..................   88
      6.3.1.  Built-in Header Semantics ...............   88
      6.3.2.  Restricting Use of Email ................   91
      6.3.3.  Load Average Computation ................   92
      6.3.4.  New Database Map Classes ................   92
      6.3.5.  Queueing Function .......................   92
      6.3.6.  Refusing Incoming SMTP Connections ......   93
      6.3.7.  Load Average Computation ................   94
   6.4.  Configuration in src/daemon.c ................   94
7.  CHANGES IN VERSION 8 ..............................   94
   7.1.  Connection Caching ...........................   94
   7.2.  MX Piggybacking ..............................   94
   7.3.  RFC 1123 Compliance ..........................   94
   7.4.  Extended SMTP Support ........................   95
   7.5.  Eight-Bit Clean ..............................   95
   7.6.  User Database ................................   95
   7.7.  Improved BIND Support ........................   96
   7.8.  Keyed Files ..................................   96










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   7.9.  Multi-Word Classes ...........................   96
   7.10.  Deferred Macro Expansion ....................   96
   7.11.  IDENT Protocol Support ......................   96
   7.12.  Parsing Bug Fixes ...........................   96
   7.13.  Separate Envelope/Header Processing .........   96
   7.14.  Owner-List Propagates to Envelope ...........   97
   7.15.  Dynamic Header Allocation ...................   97
   7.16.  New Command Line Flags ......................   97
   7.17.  Enhanced Command Line Flags .................   97
   7.18.  New and Old Configuration Line Types ........   97
   7.19.  New Options .................................   98
   7.20.  Extended Options ............................   98
   7.21.  New Mailer Flags ............................   99
   7.22.  Long Option Names ...........................   99
   7.23.  New Pre-Defined Macros ......................  100
   7.24.  New LHS Token ...............................  100
   7.25.  Bigger Defaults .............................  100
   7.26.  Different Default Tuning Parameters .........  100
   7.27.  Auto-Quoting in Addresses ...................  100
   7.28.  Symbolic Names On Error Mailer ..............  100
   7.29.  SMTP VRFY Doesn't Expand ....................  100
   7.30.  [IPC] Mailers Allow Multiple Hosts ..........  101
   7.31.  Aliases Extended ............................  101
   7.32.  Portability and Security Enhancements .......  101
   7.33.  Miscellaneous Changes .......................  101
8.  ACKNOWLEDGEMENTS ..................................  102
Appendix A.  COMMAND LINE FLAGS .......................  104
Appendix B.  QUEUE FILE FORMATS .......................  106
Appendix C.  SUMMARY OF SUPPORT FILES .................  109