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If you do not have a TCP/IP channel in your configuration you can create one by adding a channel block to the PMDF configuration file that looks like this:
tcp_local single_sys smtp TCP-DAEMON |
tcp_local
and the single_sys
and smtp
keywords are required. The single_sys
keyword tells PMDF that only a single system is allowed in each message file since each message file will be associated with a single TCP connection. The smtp
keyword activates the SMTP parser routines.
Rewrite rules need to be added to the configuration file to map system or domain names onto the tcp_local
channel. If you used the PMDF configuration generator and told it that you wanted TCP/IP support, it should have already produced applicable rewrite rules. Note that since the single tcp_local
channel can connect to many hosts, the channel host name is the pseudonym TCP-DAEMON
. Rewrite rules should rewrite to the pseudonym, and not simply to the
destination host. For example:
NODE.EXAMPLE.COM $U%$D@TCP-DAEMON |
The multithreaded TCP SMTP channel supports domain literal addressing. Internet Requirements (see RFC 1123) mandate that an Internet host be able to accept a domain literal specifying its own IP address. You should add a rewrite rule to your configuration file of the form
[1.2.3.4] $U@official-local-host-name |
1.2.3.4
is your IP address and official-local-host-name
is the official host name on your local channel. If all other domain
literals are to be targeted to the channel a rewrite rule of the form
[] $U%[$L]@TCP-DAEMON |
If many systems accessible via TCP/IP are grouped in a couple of common domains, the use of more general rewrite rules should be considered. For example, suppose that a large number of systems in the .example.com
domain are accessible via TCP/IP. Then the rewrite rule
.EXAMPLE.COM $U%$H$D@TCP-DAEMON |
.EXAMPLE.COM
domain can be reached via TCP/IP. Exceptions (e.g., systems in the .EXAMPLE.COM
domain that are not reachable via TCP/IP) can be handled by inserting
additional more specific rewrite rules.
The only disadvantage to this scheme is that errors like sending to a nonexistent system in the .EXAMPLE.COM
domain will not be detected until PMDF actually attempts to deliver the
message to the nonexistent system.
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