In 1.8b, you can "SET userid@host NOPOST" or "SET userid@host REVIEW".
The first simply bounces any attempt to post back to them, the second
forwards their postings to the list owner (or editor) with a note to
them that says their posting has been forwarded to the editor for
approval.  (You can also do "QUIET SET userid@host NOPOST"  or "QUIET
SET userid@host REVIEW" depending on whether or not you want them to
know that you changed the setting.)
 
The only problem with this is that they can always unsub and resub
to clear the setting.  This has been discussed on this list extensively
and you should be able to do a database search on NOPOST to get copies
of the discussion.
 
Nathan
 
On Tue, 30 Jan 1996 09:09:19 EST Tim Smith, Trenton State College said:
>Can I set certain users to receive mail only?
>We have a list on campus that many people use. Certain individuals love to
>flood this list with propoganda, nonsense, and garbage. Upper management says
>that it is NOT an option to delete them from the list.
>
>Any ideas are welcome. Thanks for your time and attention.