PMDF System Manager's Guide

PMDF automatically returns undeliverable messages after a certain amount of time has elapsed. (See Section 1.4.4.) However, UUCP maintains its own queues for files, so it is possible for messages to get stuck in the UUCP queues where PMDF's regular message return job cannot see them.

Thus, an additional periodic cron job is needed to return undeliverable UUCP messages. This job operates in the same way as PMDF's regular message return job except that it scans the UUCP queues and not the PMDF queues. This job is scheduled by the cron daemon.