Cloudmark, a stealth startup, plans to offer a new approach to automated spam filtering soon. Part of it is an open-source technology called Vipul’s Razor that has been around for a few months. One of the founders, Vipul Ved Prakash, is speaking at the O’Reilly Emerging Technology Conference in mid-May. Spam is an increasingly serious problem, and existing solutions such as Brightmail are of limited effectiveness. It will be interesting to see what Cloudmark brings to the table.