I have just discovered the K9 Spam Filter!

It works by checking every email that comes in to your computer and tags emails that it thinks is spam. Then you can sort the spam from the rest with your message rules in your email program.

You then train it what is spam and what is real email, and it starts to learn how to spot spam, making your inbox cleaner and cleaner.

I've only had it on a few days but it is working well already :)