What is the best free Spam Filter available?

[wilsarnie]

Any recommendations?

I'm fed up of receiving emails how to "'e'n'l'ar'ge' my penis" (I'm a girl!!), and telling me to "invest in this great venture".

[fo3nix]

What email system do you use?

If you use a web-based system with no way of getting it through a client like Thunderbird, then you're really at the peril of your provider.

If you can get your email through a mail client like Thunderbird, then that has a good bayesian filter that'll really help.