sendmail, 4th Edition

How to Declare Queue Groups with the m4 Technique

You declare queue groups inside your mc configuration file with the QUEUE_GROUP mc configuration macro. As you saw in the previous sections, it is used like this:

QUEUE_GROUP(`group name', `equates')

The queue group name can contain any characters except a comma or a whitespace character (a space or a tab).^[184] It must not be surrounded (inside the quotes) with whitespace characters.

The equates form the second argument to the QUEUE_GROUP mc configuration macro. The equates are described in The Q Configuration Command on page 409.

To illustrate, consider the following QUEUE_GROUP mc configuration macro declaration:

QUEUE_GROUP(`slowmail', `P=/var/spool/mqueues/slowqueue')

Here, the name of the queue group is set to slowmail. The second argument is a single equate, the P= queue-group equate, which defines the queue directory or directories to be used by this queue group.

If you want to define which queue group to use for certain delivery agents, you can use the Q= delivery-agent equate (Q= on page 750) as set, for example, with the LOCAL_MAILER_QGRP mc macro. For example, the following tells sendmail to queue all local mail in the /queues/lq queue directory:

QUEUE_DIR(`/queue')
QUEUE_GROUP(`localgroup', `P=/queue/lq')
define(`LOCAL_MAILER_QGRP', `localgroup')    ← must be before MAILER(local)
MAILER(`local')

In the first line we set the default queue directory. In the second line we define the queue group localgroup, and set its queue directory ...