Path: utzoo!attcan!uunet!mcvax!ukc!etive!glasgow!steve
From: steve@mrc-apu.cam.ac.uk (Steve Platt)
Newsgroups: comp.mail.sendmail,mail.uk-sendmail-workers
Subject: Re:  Sendmail problems
Message-ID: <6053.8907251628@kocab.mrc-apu.cam.ac.uk>
Date: 25 Jul 89 16:28:28 GMT
Sender: daemon@cs.glasgow.ac.uk
Lines: 28

| Every so often incoming uucp mail gets as far as our machine, but then
| stays in /usr/spool/mqueue as a df... file with no corresponding qf...

| Has it happened to you? Have you overcome it?
Yes and no (in that order!)

We have had trouble like this for a long time.
I also found core dumps from sendmail in the mqueue directory
and incomplete logs in the syslog file  - ie just one line
with sendmail announcing it was starting up.
As sendmail is setuid, it doesn't always core-dump of course...

It seemed (sometimes at least) to be related to "domain unknown" errors.
The most recent example looked like an attempt for our
system to send a "return receipt" acknowledgement to an
address with no known domain in it - instead of the local
postmaster getting sent a "domain unknown" error report
mailed back, sendmail coredumped.

We also noticed that users "mailing" to unknown domains
using Mail got the "domain unknown" message from sendmail
printed on their terminal then instead of a dead.letter
file or a return mail message, there was nothing - just
another "df" file in mqueue; and if the user concerned
was in fact root, then a "core" file too.

Sorry the above is so long and rambling, I just hope it
jogs someone's memory somewhere!