PMDF System Manager's Guide

Sometimes it is convenient to configure PMDF to route mail not for the local host, or a group of local machines, to a central machine and leave it up to that machine to deal with the mail, perhaps relaying it to the outside world or other local machines, or perhaps even gatewaying it into other mail systems. The following example configuration, Example 2-3, illustrates doing just this. The local host is HOSTA.EXAMPLE.COM and two other local machines, HOSTB.EXAMPLE.COM and HOSTC.EXAMPLE.COM, are recognized. Mail for either of those two machines is sent via a tcp_local channel (SMTP over TCP/IP) to those hosts. All other mail not for HOSTA, HOSTB, or HOSTC is sent via another SMTP over TCP/IP channel, named tcp_gateway, to the host MAILHUB.EXAMPLE.COM. A "match-all" rule is used to direct all mail not for HOSTA, HOSTB, or HOSTC to that channel. (The match-all rule is described in Section 2.2.4.3.) The daemon keyword is used with the tcp_gateway channel; the usage of this keyword with SMTP over TCP/IP channels is discussed in Section 2.3.4.81. It tells the channel to route messages queued to it through the host MAILHUB.EXAMPLE.COM.

Example 2-3 Routing Messages to a Central Machine

! ! Rewrite rules for the local host/cluster ! HOSTA $U@HOSTA.EXAMPLE.COM HOSTA.EXAMPLE.COM $U@HOSTA.EXAMPLE.COM ! ! Rewrite rules for some internal systems ! HOSTB.EXAMPLE.COM $U%HOSTB.EXAMPLE.COM@TCP-DAEMON HOSTC.EXAMPLE.COM $U%HOSTC.EXAMPLE.COM@TCP-DAEMON ! ! Use a match all rule to route everything ! else to the MAILHUB.EXAMPLE.COM ! . $U%$H@MAILHUB.EXAMPLE.COM$A l HOSTA.EXAMPLE.COM tcp_local smtp single_sys mx TCP-DAEMON tcp_gateway smtp mx daemon router MAILHUB.EXAMPLE.COM