[Mailman-Users] bounce message with non-members

[Anne Ramey]

What does this message mean in the bounce log?
bounce message with non-members of ...

I have a separate list for a customer with aol addresses because of 
their very strict rules, but it appears that the bounces for that list 
are going to another lists and I'm getting these non-member messages.  
I've checked the alias for bounces and it's correct:

AOLlist-bounces:      "|/usr/local/mailman/mail/mailman bounces AOLlist"

???any ideas?

Anne