I have a subscriber who belongs to two lists on our server 
<tr.wou.edu>, a sub site of <wou.edu>

Recently, I have been receiving the following error from both lists

11 08/10 08/21 [log in to unmask]
Last error: 5.1.1 550 5.1.1 unknown or illegal user: user@s21699

The address in the subscriber lists for this person is <[log in to unmask]>

If this weren't happening daily, I would assume it was just a spammer's 
spoofed address. Both lists are private.

------------
Regards,
Randy Klumph
[log in to unmask]

The Teaching Research Institute
Western Oregon University
345 N Monmouth Ave
Monmouth, OR 97361

http://www.tr.wou.edu