Blocking spam

[Brian Horvitz <horvitz () websecure net>]

Can someone give me a clue on filtering mail on using the stock sendmail
that comes with Solaris?  I am unfortunately without a sysadmin right now
(anyone need a job?) but I do know enough to monkey with what needs
monkeying.  Anyway, a certain user decided to dial up (to somewhere
else) and use my mail system to send mail to every single AOL user.  Today
alone I probably got about 600 copies of his bounced mail...never mind
that this is deffinately not cool.  Anyway, I have the email address that
he is using as for the FROM: field so I'd like to simply block that out.
Help would be appreciated.

        Brian