[Mailman-Users] Mailman/VERP problems.

[Aaron Crosman]

After several months of a nicely functioning Mailman server, I opted to
enable VERP yesterday. We're running MM 2.1.4 on SuSE with exim.  Since
then most everything has worked fine, until an announcement only list of
4000 sent a message earlier this afternoon.  Of the roughly 4000
messages, about 1600 are now frozen in the exim queue.

The exim queue has lots of entries like this:
2005-02-03 12:27:31 1CwklP-0002Rm-5i <=
listname-bounces+namepart=domain.tld at server.org H=localhost (server.org)
[127.0.0.1] P=esmtp S=47504 id=BE27BA2C.1291%sender at host.org
2005-02-03 12:27:31 1CwklP-0002Rm-5i ** namepart at domain.tld R=dnslookup
T=remote_smtp: SMTP error from remote mailer after RCPT
TO:<namepart at domain.tld>: host mxb.earthlink.net [207.217.125.26]: 550
namepart at domain.tld...User unknown
.
.
.
2005-02-03 12:27:32 1CwklP-0002S1-Rp ** listname at server.org
<listname-bounces+namepart=domain.tld at server.org> R=mailman_router
T=mailman_transport: 
Child process of mailman_transport transport returned 6 from command:
/usr/lib/mailman/mail/mailman

Resulting in the following from syslog:
Feb  3 12:27:32 list Mailman mail-wrapper: Illegal command:
bounces+namepart=domain.tld


It seems that suddenly large numbers of addresses are suddenly bouncing.
Mailman is then chocking on the bounces.  I followed the instructions
from http://www.exim.org/howto/mailman21.html#verpin when I setup VERP.
I'm not carefully reviewing those changes to check for mistakes.

If anyone has insight into why so many addresses are suddenly bouncing,
and why mailman is chocking on the bounces I would very much appreciate
it.

The other detail worth mentioning is that several smaller lists are
continuing to function properly.  This list was transferred some time
ago from another server.  There were some minor changes I had to take
just after the migration to deal with odd settings that came in when the
lists were moved.  Everything seemed to be fine, but now I wondering if
I missed something during the move.