Use the cleanque(ADM) program to remove outdated files from the mail queues. Use crontab(C) as mmdf to run cleanque daily. You might want to run cleanque more often, depending on your mail volume. You can also run cleanque using cron(C). To do this, create a crontabs file for mmdf in the /usr/spool/cron/crontabs directory that includes this line:
0 0 * * 0-6 /usr/mmdf/bin/cleanqueYou can also run cleanque by hand whenever you suspect a problem with mail delivery. The cleanque manual page provides a complete description of this program.