sendmail, 4th Edition

Rule Set Queue Group Selection

Normally, the access database, described earlier, is the easiest way to select queue groups. There might be times, however, when selecting by recipient address or domain is not sufficient. Should such a situation arise, you could set up your own rule sets. But be forewarned that if you do, the FEATURE(queuegroup) cannot be used. If you try to use both, you will get the following warning every time sendmail starts to run:

WARNING: Ruleset queuegroup has multiple definitions

The first step in declaring your own rules to select queue groups is to declare a special rule set called queuegroup. You do that in your mc configuration file using the LOCAL_RULESETS macro:

LOCAL_RULESETS
Squeuegroup
               ← your rules here

The way this rule set works is simple. Any queue group for a recipient address that a rule selects is returned following the $# operator. For example, consider the following:

R $*                                          $: $>canonify $1
R $* <@some.domain>          $# somegroup

Here, mail bound for any user at some.domain will be queued in the somegroup queue group.

Normally, queuegroup rule sets are used to select queue groups based on the recipient. If you wish to select based on the sender, you can do so using rules something like the following:

LOCAL_RULESETS
Squeuegroup
R $*                     $: $>canonify $&f
R $+ <@ lists.domain.>   $# lists

First, we fetch the sender address using $&f, and pass it through the canonify rule set 3 to focus on the host part. The second rule matches any user at the domain lists.domain