[Mailman-Users] password reminders, subscribers with listname at xyz.com?

[Dewhirst, Rob]

I have a mailing list set up to send monthly password reminders.

Today, two of these reminder messages ended up in the Administrative
requests for the list as being posted to the list from non-members.

Coincidentally, the subscriber's email addresses are
nameofproblematiclist at xyz.com.  Their email address usernames are the
same as the name of the problematic list sending out the password
reminders, but their complete email address is in another domain.  

I am running Mailman 2.1.8 on RHEL4 with Exim.

Any ideas? I suppose I could post headers if this is not clear.