Spam URL real-time block lists or SURBLs are said to differ from most other real-time block listings in that they block messages based on the domain names or URLs in the message body. Spam detection rates with SURBLs are running at 40% to 60% with near-zero false positives
Red Earth said that in order to bypass existing heuristic and Bayesian filters, many spammers are replacing text with images or including minimal text with a website link. However, since spammers must provide a means to be contacted, nearly all spam messages include a URL that can be filtered using spam URL real-time block lists.
Red Earth’s Policy Patrol 3.5 will support SURBL lists. Policy Patrol is a suite of anti-spam, anti-virus, content and attachment checking software for Microsoft Exchange and Lotus Domino/Notes systems that competes against similar product lines from the likes of SurfControl Plc. and ClearSwift Ltd.
