Commtouch fights spam at gateway

Commtouch Software, which uses digital signature technology to detect unwanted e-mail, last week released a version of its product designed to appeal to large companies.

The company's Anti-Spam 4.0 software uses Commtouch's statistical approach, called Recurrent Pattern Detection (RPD), to filter spam at an organization's gateway, says CEO Gideon Mantel. The previous version of Commtouch Anti-Spam resided on the mail server and worked only with Microsoft Exchange; this version resides at an organization's gateway and is compatible with any mail server, he says.

The software doesn't examine the content of a message, but creates a digital signature of each e-mail and then compares it with other incoming traffic to find patterns, such as having the same first, fourth and seventh character in the message's subject line. If the software sees a large number of e-mail messages sent at once with matching signatures, it will flag them and store them in a quarantine folder at the gateway.

To continue reading, register here and become an Insider. You'll get free access to premium content from CIO, Computerworld, CSO, InfoWorld, and Network World. See more Insider content or sign in.

Commtouch Software, which uses digital signature technology to detect unwanted e-mail, last week released a version of its product designed to appeal to large companies.

The company's Anti-Spam 4.0 software uses Commtouch's statistical approach, called Recurrent Pattern Detection (RPD), to filter spam at an organization's gateway, says CEO Gideon Mantel. The previous version of Commtouch Anti-Spam resided on the mail server and worked only with Microsoft Exchange; this version resides at an organization's gateway and is compatible with any mail server, he says.

The software doesn't examine the content of a message, but creates a digital signature of each e-mail and then compares it with other incoming traffic to find patterns, such as having the same first, fourth and seventh character in the message's subject line. If the software sees a large number of e-mail messages sent at once with matching signatures, it will flag them and store them in a quarantine folder at the gateway.

To limit an organization's storage requirements, Commtouch houses these digital signatures at its detection center in Mountain View, Calif. The software residing on an organization's gateway automatically does a DNS query to compare incoming messages with stored signatures, a process that results in almost no latency, Mantel says.

Commtouch's technology isn't looking for spam per se; it's looking for outbreaks where hundreds or thousands of identical messages are sent, Mantel adds. Therefore, the product also can be used to detect viruses, he says.

It's this digital signature approach that separates Commtouch from the competition, such as anti-spam filter maker Symantec and appliance vendors IronPort Systems and CipherTrust, Mantel says.

Perhaps the closest competitor to Commtouch is Cloudmark, which recently released its Immunity software that generates a "genetic map" tailored to meet each company's definition of spam.

"There are a variety of good techniques [for fighting spam]; this is another of them," says Michael Osterman, president of Osterman Research, of Commtouch's software. "Because of recurring patterns in spam, the RPD technique is a useful [one]."

With Anti-Spam 4.0, Commtouch charges an initial gateway setup fee of $2,500, plus $8 to $20 per user per year, the company says.

Read more about software in Network World's Software section.