i didn't see any mention of this in the majordomo FAQ, and it seems
like a useful thing to put in ...
i have for some time had an email loop going that i couldn't track
down; i would get bounce messages which appeared to be from an
infinite loop of majordomo mailing to itself. finally i figured
out what was going on; the mkdigest command was in majordomo's
crontab file, so the results messages from the digest program were
being sent to majordomo, from majordomo.
in other words, don't use the crontab for majordomo to send these
types of messages; use your own crontab file.