Matts,

A thought just occurred to me: Whenever I get spam it always seems to have a huge number of exclamation marks in it:

FREE PORN!!!!
See Britney Naked!!!
etc...

With this in mind, how about calculating the exlamation-mark-to-sentence ratio, rejecting mails with, say, more than one exclamation mark per sentence.

Tongue slightly in cheek, Elgon

"A nerd is someone who knows the difference between a compiled and an interpreted language, whereas a geek is a person who can explain it cogently over a couple of beers"
       - Elgon