[Mailman-Users] message won't post/Posfix/Mailman issues

This is a reocurring problem with one list that I host. It has 40,000 subscribers and only one subscribed address can post and I am an allowed non-subscriber who can post. When either the subscriber or I post to the list, the message is not delivered, but the Postfix maillog shows this:

May 2 11:07:56 webhost postfix/local[13508]: 4ED8F4E538: to=<listname@wherever.com>, relay=local, delay=0, status=sent ("|/lists/mail/ mailman post listname")

However, there is nothing in the Mailman/post log that shows that it reached Mailman and obviously, the message isn't posted. This may be a Postfix issue, but I am posting it to the Mailman list since it appears that the message just isn't reaching Mailman.

-- Christopher Adams