July 15, 2007
Open Source Filtering Solutions and the Spam Problem
Author: JT Smith
Let us face it, modern e-mail communication relying on SMTP is fundamentally broken - there is no sender authentication. There are lot of countermeasures in form of filtering and add-on authentication, but neither of them are proved to be 100% successful. Spammers always find new ways of confusing filters with random noise, bad grammar, hidden HTML code, padding, bitmap-rendered messages etc. This article will nevertheless try to cover some of the spam problems and possible solutions, but bare in mind that all of these are just no more than a temporary fix.
Link: Help Net Security