Introduction Product Overview Installation & Use Support & Troubleshooting Links     updated: 6/17/98

Installation & Use Configuring Mail Server Settings This section will walk you through the normal and advanced ASIP mail server settings, as well as options you have for configuring specific hosts. Mail Server Settings Advanced Settings Host Settings Related Topics Mail Service Primer Ports & Firewalls [Advanced] Mail Server Settings Before starting the mail server, you can review and set the mail server settings, by selecting that option from the Server menu of the ASIP Mail Admin program. General On the "General" tab for the mail server settings (shown below), you have these options: Start the mail server at System Startup time. This option is recommended, as mail service cannot function if the mail server application is not running. Set the amount of free disk space that is required for the mail server to continue accepting mail. This feature prevents the volume from getting full. Set the location for the mail storage. Remember that POP clients typically download the mail to their workstations whenever they connect, so disk space requirements would be less using POP than they would with IMAP, where mail remains on the server. Select a volume that has adequate disk capacity to accommodate your mail users. For best disk storage efficiency, this volume should be formatted as HFS+. Set the maximum size for mail logs. Mail In   Message size. To set the maximum message size for incoming messages, including enclosures. Keep in mind that other mail servers may have different limitations, so a mail message that is acceptable to your ASIP mail server may be rejected by another mail server. Blind copies of all messages, both ingoing and outgoing, can be sent to a particular user or group. Note that this does not increase the total number of messages stored on the server, as only one copy of any message is stored in the mail database, regardless of how many recipients there are. Forward mail addressed to unknown users. You can select a user that has been configured on the server; this is typically the "PostMaster" account. Require Local "from" addresses to exist; this is an anti-spamming feature, which verifies that the user from whom the mail purports to be, actually exists on the server AND has mail enabled. This verification is only done when the message's "from" address is the hostname of the ASIP mail server itself. Messages from other hosts are not verified. Reject Mail if destination is not in Host List. As administrator, you can create a host list, and limit mail exchange only to hosts on that list. You can also limit mail exchange on a host-by-host basis. These features are discussed more fully below. Mail Out Message Expires after... Set the amount of time a message will attempt to be delivered before being returned to sender. The message might be undeliverable if the host is down, or network connections are down. Note that if the mail is undeliverable for other reasons (if the host name is wrong or misspelled, or the user doesn't exist on that host), the message should be returned to sender immediately with an appropriate error message ("host unknown", or "user unknown"). Relay all SMTP mail. This setting lets you choose another SMTP server to which all outgoing mail will be sent. Responsibility for delivering the messages to the individual mail servers then gets transferred to that host. This option is helpful if you have a slow link or dial up to exchange email. Be sure to make arrangements for mail relay with the administrator of the other system. Warn sender/Postmaster The notify options will alert the sender, the postmaster, or both, of mail not delivered in a timely manner. The server will continue to attempt to deliver the mail until the message expires, as indicated in the first 'Mail Out' setting. Hold Outgoing Mail This option would be useful if the network is temporarily down or changes being made. It allows users to continue sending mail to the mail server, but the mail server will queue the messages until the hold is released. Advanced Settings Once the mail server has been started, you can adjust advanced settings, if you wish. Network   Always check DNS: will send a query to the DNS server for each mail message it must deliver. The alternative is Cache DNS results: will hold DNS responses in a local cache until either the TTL expires (time to live, a value set up in DNS tables), or a user-specified number of minutes. This setting can help speed up delivery, as it saves the time needed to get a response from the DNS server. On the down side, the cached information may no longer be valid. DNS Request: In some circumstances, you may want to specify what information will be retrieved from DNS when the mail server attempts to deliver mail. Otherwise, just keep this setting at the default of MX-List & A-record. Timeouts. These are default values for how long the server will attempt to open a connection or get access ot the network before giving up. You probably wouldn't want to reduce these times, but if you're on a very busy network, or contacting busy servers, you may want to increase them. Protocols Here, you can enable different protocols, indicate how the server will identify itself on that port, and what port number it will use. SMTP Simple Mail Transfer Protocol. This is the protocol that mail servers use to accept mail from clients, and to exchange mail with other mail servers. IMAP Internet Message Access Protocol. This is the procotol that certain mail clients will use when access their mail on the server. IMAP Administrator Access This port allows the server administrator to manage the mail server remotely. Using this port requires an IMAP client that supports nested folders and the ability to change the port to which you will connect. Only server administrators would be allowed to connect to this port. POP3 is the third implementation of Post Office Protocol, which is what POP clients use to retrieve their mail from the mail server. PASS allows a mail client to change his or her password. This feature must also be supported in the mail client software. FINGER allows a client to lookup a list of mail accounts on the amil service, providing information from the Users & Grops data file. This feature must also be supported in the mail client software. NOTIFY will alert the client when new mail has arrived. This feature must also be supported in the mail client software. Changing the port number may prevent other servers from communicating with you. SMTP servers attempt to connect at port 25, which is a "well-known" port used for SMTP connections. If you change the port number for incoming SMTP connections, other mail servers will not be able to open a connection to deliver mail to you, unless they somehow are aware of the new port your server is listening on. If the port numbers are changed by mistake, the "Use Default" buttons will return them to their original values. Logs This screen allows you to specify what type of messages will be captured in the Server Log and the Error Logs. The default setting of "all on" results in some very meaningful feedback in the logs, such that troubleshooting problems can be made very easy. See Troubleshooting Mail Server section for details about what errors can be found in the server and error logs. Host Settings ASIP Mail server lets you indicate preferences on a host-by-host basis. As you exchange mail with various hosts, they will appear in the Hosts List (choose "Show Host List" from the Server menu). You can also add hosts to this list, by creating a host. You can view what the default settings are for each new host by selecting "Edit Default Host Profile" from the Server menu, once the Hosts Lists is displayed. This template is what is used for all new hosts that your mail server sends mail to. Change the template as needed. For each host, you can set the following options: Mail From   Allow from the host enables that mail server, or host, to send you mail. Deliver mail from host to local addresses, but don't accept mail that needs to be relayed to other SMTP hosts. Log recipient rejection to error log, will log any attempts to deliver mail to an invalid recipient (a user or group not on your mail server, or with mail disabled). Send bcc of all messages from this host to: allows you have a user or group monitor incoming mail from this host. Reject all mail from this host. This option might be used when users complain of receiving unwanted advertisements or spams from a specific host. Log each rejection. Mail To   Allow mail to host will enable users to send mail to this host. Message expire after X hours: if the mail is undeliverable because host cannot be communicated with, the mail will be returned to sender after this period of time. Note that errors such as "no such host", or "no such recipient", will cause the mail to be rejected and returned to sender immediately. Relay all SMTP mail via: lets you set up another SMTP host to relay all mail to the destination host. Notify sender of non-delivery alerts the sender that the mail has not been delivered in a timely manner; the mail server will continue attempting to delive the mail message until it expires. Hold mail to host Delete mail to host, with options to notify the sender and/or the postmaster. Schedule   Connect as needed is the default, and is what is normally used with a direct connection to the Internet. The alternative is: Set allowed connection times would most likely be used with a dialup connection; you could for example, set your mail server to let mail queue up, and only connect to deliver it several times a day, indicated by the green squares on the schedule. (show me). Retry frequency is the interval at which the mail server will make another attempt to deliver mail, should previous attempts have failed. Remote mail polling lets you "ping" other mail servers who may have mail to be delivered to you, so they know your mail server is now on line, and they can attempt to deliver the mail. This feature is very useful when you have a dial up connection for mail exchange. Network These settings are mostly the same as those found on the Network tab of Advanced Settings. This allows you to override those settings for a particular host.   DNS Settings: As in Advanced Mail Server Settings, you can specify whether DNS lookups should be performed, DNS info cached, or to just use existing Mail Server Settings. Network timeout indicates how long the mail server will wait before timing out the connection; 120 seconds is the default, but if you know that the host is on a slow link or tends to be very busy, you might want to give it a bit more time. Custom Outgoing SMTP port. If this host is not using port 25 for SMTP connections, you can enter the correct port number to use here. Related Topics Mail Service Primer Ports & Firewalls