Mail filters in qmail?

[Dr. Evil]

Ok, I have come to the conclusion that this list is unbearable without
some filters.  Can someone recomend what is the easiest way to drop
email from certain posters, using the Qmail system?  I just want
something simple which won't require me to learn some new
super-powerful filter ruleset description language.  I just want to be
able to say, "If it comes from ravage at ... please discard."

Thanks