[Mailman-Users] Mail to some lists works, bounces for others

[Luke Tymowski]

Hello,

We have a number of mailing lists that are member-only. On most of the lists, users can post successfully. 

But on others, even though people attempting to post are members, or in one case the list owner, their mail is rejected.
"550 5.1.1 Recipient address rejected: User unknown"

There are no lock files for a particular list.

The only files in /var/lib/mailman/locks are master-qrunner and master-qrunner.mailman.2502
(The dates on those two files are more than 24 hours into the future - is that normal?)

The /var/lib/mailman/data/aliases shows the relevant aliases for that particular list.

Mailman version: 2.1.13
OS: Ubuntu 10.04.2 
MTA: Postfix 2.7.0



thanks,

Luke