The Barracuda Spam Firewall is available in four models and supports from 1,000 to 25,000 active users with no per user licensing fees. The Barracuda Spam Firewall can be installed in front of the E-mail server in typically less than five minutes and is automatically updated hourly to block new forms of spam and viruses. Its architecture leverages open source spam and virus solutions in conjunction with ten defense layers: denial of service and security protection, IP block list, rate control, virus check with archive decompression, proprietary virus check, user specified rules, spam fingerprint check, intention analysis, spam rule-based scoring, and Bayesian analysis. This architecture minimizes the processing of each E-mail, allowing the platform to process millions of messages per day.

The Barracuda Spam Firewall reduces the load placed on the E-mail server by off-loading both spam and virus filtering. Barracuda Networks also offers the Energize Update subscription service to automatically update the Barracuda Spam Firewall with the latest spam rules and virus definitions.