[Exim] Double messages

Hello Exim Users,

We've been enjoying exim with majordomo for several months now. We
run over a dedicated phone line (still) and have a problem sometimes
when our line gets dropped. Sometimes we find it necessary to turn
our modem off and on to get going again. But, when we do, we have a
high probability of getting a duplicate message or two going across a
list.

The first of the duplicates is always caught behind a "Spool file is
locked" situation. Apparently, it can be locked for days without a
retry.

This last time, I did a thorough study of the history of the duplicate
message and read everything in the Exim manual about spool locking and
I'm at a loss to figure out what to do.

If anyone can help, here are the relevent entries from the logs:

Here's the original message coming in:

2000-03-17 11:28:56 12W2Qa-0006Np-00 <= marilyn@??? U=marilyn P=local-esmtp S=2952 id=Pine.LNX.4.10.10003171125340.672-100000@???
2000-03-17 11:28:59 12W2Qd-0006Nx-00 <= owner-mln-chat@??? U=majordom P=local S=3247 id=Pine.LNX.4.10.10003171125340.672-100000@???

Now we start delivery:

2000-03-17 11:29:23 12W2Qd-0006Nx-00 => |/usr/local/majordomo/wrapper archive2.pl -f /u1/majordomo/archives/mln-chat/mln-chat -m -a (mln-chat-archive@???) <mln-chat-outgoing@???> D=system_aliases T=address_pipe
2000-03-17 11:29:23 12W2Qd-0006Nx-00 => marilyn <mln-chat-outgoing@???> D=localuser T=local_delivery
2000-03-17 11:29:25 12W2Qd-0006Nx-00 => |/usr/local/majordomo/wrapper digest -r -C -l mln-chat-digest mln-chat-digest-outgoing <mln-chat-outgoing@???> D=system_aliases T=address_pipe

Then we have 29 successful deliveries. Then the 30th at:

2000-03-17 11:30:48 12W2Qd-0006Nx-00 => vince@??? <mln-chat-outgoing@???> R=lookuphost T=remote_smtp H=mail.lrpubs.com [205.178.34.190]

This first report of a lock makes sense since some process is still working
on it:

2000-03-17 11:30:49 Start queue run: pid=24564
2000-03-17 11:31:55 12W2Qd-0006Nx-00 Spool file is locked
2000-03-17 11:31:55 End queue run: pid=24564

Still working on it:

2000-03-17 11:43:57 12W2Qd-0006Nx-00 mx01.mindspring.com [207.69.200.44]: Connection timed out
2000-03-17 11:43:57 12W2Qd-0006Nx-00 mx01.mindspring.com [207.69.200.184]: Connection refused
2000-03-17 11:43:59 12W2Qd-0006Nx-00 => kimgould@??? <mln-chat-outgoing@???> R=lookuphost T=remote_smtp H=mx03.mindspring.com [207.69.200.38]
2000-03-17 11:44:02 12W2Qd-0006Nx-00 => etymes@??? <mln-chat-outgoing@???> R=lookuphost T=remote_smtp H=mail.lts.com [170.1.53.67]

Now, apparently this process has given up and never again tries any
deliveries but has left the lock on the spool file:

2000-03-17 11:45:49 Start queue run: pid=24659
2000-03-17 11:45:49 12W2Qd-0006Nx-00 Spool file is locked
2000-03-17 11:45:49 End queue run: pid=24659
2000-03-17 12:00:49 Start queue run: pid=24774
2000-03-17 12:00:49 12W2Qd-0006Nx-00 Spool file is locked
2000-03-17 12:00:49 End queue run: pid=24774
2000-03-17 12:15:49 Start queue run: pid=24852
2000-03-17 12:15:49 12W2Qd-0006Nx-00 Spool file is locked
2000-03-17 12:15:49 End queue run: pid=24852
2000-03-17 12:30:49 Start queue run: pid=24910
2000-03-17 12:30:49 12W2Qd-0006Nx-00 Spool file is locked
2000-03-17 12:30:49 End queue run: pid=24910

These continue, even today!!!

2000-03-18 16:52:24 12W2Qd-0006Nx-00 Spool file is locked

Here we recycled the modem, the computer stayed up, and who generated
this? You can tell by the id that it is the same message.

2000-03-18 16:52:26 12WTxC-0000Fn-00 <= owner-mln-chat@??? U=majordom P=local S=3247 id=Pine.LNX.4.10.10003171125340.672-100000@???
2000-03-18 16:52:46 12WTxC-0000Fn-00 => |/usr/local/majordomo/wrapper archive2.pl -f /u1/majordomo/archives/mln-chat/mln-chat -m -a (mln-chat-archive@???) <mln-chat-outgoing@???> D=system_aliases T=address_pipe
2000-03-18 16:52:46 12WTxC-0000Fn-00 => marilyn <mln-chat-outgoing@???> D=localuser T=local_delivery
2000-03-18 16:52:48 12WTxC-0000Fn-00 => |/usr/local/majordomo/wrapper digest -r -C -l mln-chat-digest mln-chat-digest-outgoing <mln-chat-outgoing@???> D=system_aliases T=address_pipe
2000-03-18 16:52:53 12WTxC-0000Fn-00 => chee@??? <mln-chat-outgoing@???> R=lookuphost T=remote_smtp H=SMTP.slac.stanford.edu [134.79.18.80]

etc. until it finished! Even the mindspring addresses did fine.

2000-03-18 16:55:09 12WTxC-0000Fn-00 => tbattey@??? <mln-chat-outgoing@???> R=lookuphost T=remote_smtp H=Leland.stanford.edu [171.64.14.7]
2000-03-18 16:55:09 12WTxC-0000Fn-00 Completed

But the original message is still locked:

2000-03-18 17:07:24 12W2Qd-0006Nx-00 Spool file is locked

etc.

2000-03-22 10:03:44 12W2Qd-0006Nx-00 Spool file is locked

Any advice?

Marilyn