John Turley, MD of the London-based company, said conventional mail filtering services such as those offered in the US by companies like Postini and FrontBridge, and in the UK by MessageLabs and BlackSpider, work by altering the Mail Exchange Record within the Domain Name System, such that all emails are rerouted to their servers for filtering, then forwarded to the destination.
That’s fine for a big enterprise customer, but not residential or SoHo customers, whose emails will be on a shared domain, he went on. A change to the MX Record means all email accounts on that domain will be changed, which means they will all have their messages forwarded to the filtering service, making it impossible for the ISP to sell the service on a subscriber-by-subscriber basis.
For that reason, Checkbridge developed a piece of code called Mail Redirector that plugs into the ISP’s email servers that enables them to decide whether mail to a particular mailbox should be forwarded directly or rerouted through the filtering service. We make mail filtering for residential and small business customers a commercial opportunity for ISPs, Turley argued.
Checkbridge uses spam filtering technology licensed from Cloudmark Inc, which can filter mail on its servers or, if the customer prefers, on a purpose-built appliance on his or her premises. Turley said the Cloudmark technology differs from most AS filters like SpamAssassin, in that it carries out analysis of the structure of the message to detect suspect mails, rather than using a rules-based approach.
In AV, Checkbdige is using three packages, namely the VSAPI engine from Trend Micro, NOD3 from eSet and the open-source Clamav product. Here again, he argued that the NOD3 package from eSet differentiates Checkbridge’s offering in that it uses heuristics as the basis of its inspection rather than signatures.
The start-up is using its first customer, UK-based Claranet, as a reference customer, since it is serving it in four countries (UK, France, Germany and Spain). As for markets beyond Europe, Turley said the company was considering licensing Mail Redirector for use in the US, a market that is too big and competitive for Checkbridge to tackle under its own stream.
