You should use SpamArrest.
You only receive e-mail that is either authorised by yourself or by the sender and most of this shit is automated so it never gets authorised.
You can still check through the stuff that hasn't been authorised.
Here is a quick summary of mine.
Messages Processed 7290
Messages Forwarded 425
Thats more than 6500 spam eliminated.
$20 for 6 months, money well spent.
Mick
http://spamarrest.com/affl?1270505