I have several users who subscribe from systems.  Since the hostname is
incorrect (smtp says host is unknown), the mail bounces.  I have served
the userid off and removed him from the list, but he keeps resubscribing,
and he is somehow no longer served out.
 
1.  Who can serve the user on?
 
2.  How can I absolutely prevent the user from being served on?
 
one user in particular is on austen.notis.com
 
jr