the recent addition of x-beenthere mail headers for Google Apps For Your Domain (gafyd) groups stopped my mailman setup working. I thought I'd share it here in case anyone else is asking about it.
I have mailman running on server.example.com
I have example.com set up as google apps for your domain with gmail
on my server I had firstname.lastname@example.org run the mailman binary with post to list whose email address is listed as email@example.com
this was working perfectly however since Sep 17th 2009 gafyd is inserting x-beenthere: firstname.lastname@example.org which /var/lib/mailman/
Mailman/Handlers/Approve.py detects as a loop and mailman mysteriously drops the message with a log in
/var/lib/mailman/logs/vette " (3902) Message discarded, msgid: ...."
the solution to me was to move the list to a non gafyd domain :(