I saw a review of Norton Anti-Spam 2004 by Symantec in PC World magazine this month and they gave it very good reviews. So I went out and bought it today. Buying it gives you a year subscription to their LiveUpdate service. It works VERY WELL. And it gives you some cool statistics statistics.
For instance 30.3% of my e-mail today (since I installed it) has been valid e-mail. 69.7% was spam.
The program adds a toolbar to Outlook that allows you to mark mail as spam, or as valid mail if NAS misidentifies it along with some other functions like emptying the Spam folder.
I've only had two or three e-mails in my inbox that I considered spam and since the program learns from you I expect that will improve over time. That is compared to 20-60 per day I had with with MailWasher.
When paired with the anti-spam features already built into Outlook 2003 I'm very pleased.
Disclaimer: I don’t work for Symantec. I’m just a happy customer.