I need .procmail tips, ban "The Bat" totally. etc

Basically half my spam is from “The Bat !” mailer and I don’t know why anyone would ever use a $40 email program for anything BUT spam due to all the “features” it has (i.e. Send anonymous spam to address book).

I’m just sick of The Bat ! and I want to make an auto-reply which bounces the message straight back whenever The Bat ! is detected - BEFORE it gets to my inbox, during the SMTP handshake or whatever! (or delete it, or add Spam Assassin score etc).

The problem is that I have no idea how to set this up and all the info is way too technical.