Barracuda Networks has added real-time malware protection to its email security appliances.

Barracuda Real-Time Protection uses the company's installed base of 40,000 Spam Firewall appliances to monitor email traffic in search of emerging threats, according to company officials.

The technology creates binary signatures or fingerprints of message components, including body text and images and attachments. The appliances scan inbound email for messages that match known fingerprints and sends these messages Barracuda's threat centre for analysis by engineers, officials said.

By analysing these messages, engineers can spot a malware breakout based on the message's volume, source or metadata. The company said it then downloads an alert to appliances so they can block messages with the same fingerprints.

The company also adds the new malware to the spam and virus definitions of known threats used by Barracuda appliances.

Barracuda's Real-Time Protection is available free of charge to existing appliance users who subscribe to the company's Energize updates. Barracuda's Spam Firewall appliances start at $899.