[Mailman-Users] Post by non-member to a members-only list

[Michael Goodman]

I keep getting bounced messages with the error "Post by non-member to a
members-only list".  The user is not a member of the list but is added
under "List of non-member addresses whose postings should be
automatically accepted ".  I'm using Mailman 2.1.5 and Exim 4.34 on
RedHat Enterprise Linux 3.0.  Any ideas?  How to I troubleshoot this? 
I've looked through the logs and haven't found anything.  Thanks.