Guide to the Ratings

Overall score is based primarily on the ability to recognize valid e-mail and spam. Filtering accuracy indicates how well each product correctly identified spam without inadvertently tagging good e-mail as spam. We used 1,000 actual spam messages captured from e-mail and 333 non-spam messages to test each program's ability to weed out spam without also putting the kibosh on legitimate messages. A product that integrates with mailer blends its own controls with those of the e-mail program. One that learns from mail identifies patterns in your e-mail, if you tell the software which messages are spam and which are not. With online collaboration, a product checks each message against a "live" online database of reported spam messages to improve accuracy. Uses rules indicates detection of known attributes, such as whether it contains a suspicious link. All products let you add "friendly" and "unfriendly" senders to the filter (either automatically or manually). Price is for the download version of the program and includes a year of service (a free trial period of at least 15 days is available). Some products are available in a boxed version for about $10 extra. (Most will mail a CD for a few dollars.)