Symantec Corp. on Wednesday launched an optional, anti-spam subscription service for customers of its Internet e-mail gateway and enterprise-class antivirus products.

Symantec Premium AntiSpam is an add-on subscription service to Symantec Mail Security and Symantec AntiVirus Enterprise Edition, officials with the Cupertino, Calif., company said. The new service, which is powered by Brightmail technology acquired by Symantec in June, is scheduled to be available later this month.

The add-on service, which doesn't require IT administration or additional software or hardware, includes more than 20 filtering technologies. Among the technologies used are spam signatures, heuristics, reputation filters, language identification and proprietary methods. Automatic updates occur every 10 minutes.