Besides the built-in junk mail filtering in Microsoft Outlook 2003, I have never found a free anti-spam program worth keeping, so all that follows in this category is payware.
With five levels of filtering available, McAfee SpamKiller (see Figure 12.6) is designed to keep junk mail out and let legitimate email messages in. It works well with most popular email programs (note for geeks : all POP3 clients ), such as Outlook Express. Rules can also be set to tell SpamKiller how to deal with different types of spam messages. You can add people to your friends list to ensure you receive their emails, or you can add addresses to your blocked senders list to keep spam out. It's a decent solution, but lets some spam through and sometimes blocks legitimate emails.
Figure 12.6. McAfee SpamKiller is a decent anti-spam product with five levels of automatic spam filtering.
Everyone who uses Cloudmark Desktop helps guard against spam. If a commercial email slips into your inbox with this program installed, you use the program to mark it as spam and it tells the Cloudmark server. Everyone benefits. When enough people mark a piece of spam, the program starts to automatically filter inboxes for that message for all Cloudmark users. The program is a plug-in available for Outlook or Outlook Express. It has a high hit rate and rarely marks a legitimate email as spam. Highly recommended!
This spam blocker works through an online web service rather than through an application installed directly on your computer. Your inbound email is filtered through the service and your email program in term fetches the cleansed email from the service. Setup is difficult, and many web-based email accounts are not compatible with Spam Arrest. It works with a challenge/response system. If an email sender is not known to the system, he gets an email asking him to type in a code. When he does, the system recognizes him as a human (spam is sent by machines so they can't respond to the challenge) and the sent email is passed on to the recipient. It stops all spam, but tends to block newsletter subscriptions and other legitimate automated emails. You have to manage those manually.