Norton Antispam is different to many other spam filters in that it filters your email transparently. It sits directly between your email client and the mail server at your ISP or email provider. The advantage of this is easy configuration as Norton Antispam doesnt connect directly to your mail server. The downside is that the whole of the email is downloaded to your PC, which could be a concern if you are using a slow dial-up modem connection.When you receive email it is checked first by Antispam which examines the header information against its builtin spam filter rules. These are updated regularly via Nortons LiveUpdate and 12 months of updates are included with the product.
Norton AntiSpam will work with any POP3-compliant email program by adding a “spam” tag in the Subject field. It is then up to you to confirm your email client on how to handle the "spam" tag. You can just use tag as a visual notification of spam email or create a rule to automatically move the tagged emails to a junk folder.
If you use Microsoft Outlook, Microsoft Outlook Express, or Qualcomms Eudora Antispam is more tightly integrated by addition of spam-fighting functions to the toolbars of these email clients.
Allowed lists ensure the email from your trusted friends and family etc is never tagged by accident as being spam.
Overall a good spam filtering tool, especially if you use a version of Outlook or Eudora on a broadband connection.