you can use sendmail's access table feature, see www.sendmail.org i have almost 700 domains/networks blocked in mine.
you can add custom messages to it too which is cool.
Got nothing better to do with your day than constantly update the list?
http://www.orbs.org would be my vote.
Since you're running Sendmail 8.9.3, all you need to do to fire it up is add
FEATURE(orbs)dnl
to your sendmail.mc file, then do a /etc/newmailconfig
Too easy!!!
-- Andrew P. Gardner
Never underestimate the power of stupid people in large groups.
