[Mailman-Users] Subscriber email doesn't post

[Bob McLeran]

On a list which I administer as owner, we have a subscribed address 
ending in "@mail.com" whose email to the list will not post. Originally, 
his posts were returned to him with a "Delivery Status Notification" 
subject line, stating: 
----------
      This is an automatically generated Delivery Status Notification. 

Delivery to the following recipients was aborted after 0 second(s): 
-----------
Initially, I did not receive a bounce notification as owner when this 
occurred. 

After determining that his ISP was releasing his email to our list 
address, I added his email address to the section of the admin interface 
Privacy Options/Sender Filters/List of non-member addresses whose 
postings should be automatically accepted. After doing that, I received 
bounce notifications when he sent an email to be posted, but the email 
would still not post. 

There are no spam filters which we have implemented that would cause 
this to occur. 

Any ideas what might be occurring and how to fix it?