How to block the bat!

Guys,

I am getting a lot mail which I know is from a mail program use by spammers, called the bat.

I like to know how can I write a rule to give lets say two or three points for this in the header.

X-Mailer: The Bat! (v2.00.6) Educational

Thanks for any help you can give me.

Payne Received on Wed Oct 17 22:17:33 2007