Routing

  • The .smtp Domain Suffix
  • IP Addresses as Domain Names
  • Wake-up Addresses

    • The CommuniGate SMTP module is always used as the link to the "rest of the world", i.e. if a message cannot be routed to other modules, and the recipient domain name contains dots, the message is routed to the SMTP module.

    The .smtp Domain Suffix

    All addresses with a domain name ending with ".smtp" are routed to the SMTP module (with the ".smtp" suffix removed).

    Sample:
    The server should route messages to all subdomains of the client.com domain a to a Unified account Client. But the messages to one specific subdomain, sp.client.com should be actually sent over the Internet to the sp.client.com server.
    You should put the following lines in the Router settings:
    sp.client.com = sp.client.com.smtp  ; to the Internet
    *.client.com  = <local>Client       ; to a local account

    IP Addresses as Domain Names

    The SMTP module recognizes "[xx.yy.zz.tt]" and "xx.yy.zz.tt"domains, where xx.yy.zz.tt is the IP address of your machine, so your system can accept messages even if they were sent using the [xx.yy.zz.tt] notation rather than the domain name notation.

    If the domain part of an address is the own IP address (or one of the own IP addresses) of the Server, the SMTP module replaces it with an empty string, forcing the Router to process the local part of the address. This feature allows your server to receive mail directed to something@[xx.yy.zz.tt] or something@xx.yy.zz.tt. where xx.yy.zz.tt is one of the Server IP addresses.

    The CommuniGate SMTP module checks if the domain name is one of the special IP addresses 127.0.0.1 and 0.0.0.0. These addresses are processed as the "localhost" addresses, i.e. the own IP addresses of the Server.

    Wake-up Addresses

    The SMTP module routes to itself all messages directed to the wakeup domain. The module interprets the local part of the address as a client domain name and the module processes such a wake-up message by releasing the messages queue for the specified domain.

    This feature allows the CommuniGate SMTP module to act as a back-up mail server for dial-up client hosts that do not support the Remote Queue Starting (ETRN) mechanism. If a dial-up host client.com uses your Server cgate.server.com as a back-up mail server, that client host can release its queue by sending a message to the client1.com%wakeup@cgate.server.com address.