[Mailman-Users] Mail going out to only 1 member

[Dave Jones]

I have a list named "supt" with 252 members that received an email that
only went out to 1 recipient.  After looking at the mailman smtp logs, I am
seeing a number of lists that are only sending to a single recipient but
have dozens to hundreds of members.  Nothing is showing up in the "post"
log for these problem lists.  How do I troubleshoot this deeper?  I still
have many lists that seem to be working properly and actually have entries
in the post log.

Postfix maillog
===============
Oct 10 10:36:12 lists postfix/qmgr[11957]: B1E055055B7:
from=<prvs=16239220b8=abc.xyz at theirdomain.com>, size=95926, nrcpt=1 (queue
active)
Oct 10 10:36:12 lists postfix/local[14994]: B1E055055B7: to=<
supt at lists.mydomain.com>, relay=local, delay=0.13, delays=0.02/0/0/0.12,
dsn=2.0.0, status=sent (delivered to command: /usr/lib/mailman/mail/mailman
post supt)

Mailman smtp log
================
Oct 10 10:36:15 2012 (15296) <
mailman.550.1349883373.15294.supt at lists.mydomain.com> smtp to supt for 1
recips, completed in 0.022 seconds

# list_members supt | wc -l
252