John Graham-Cumming (or jgc to the anti-spam cognoscenti) is best known as the author of the open source tool POPfile. He has now created a commercial product to build this functionality into other commercial products.
POPfile is an email classifier -- it's best known for it's ability to classify email as spam, using Bayesian analysis and other statistical methods. The new product is a library called polymail. The first commercial product to use it is the new range of MIMEsweeper email security products from Clearswift.
POPfile can be a very accurate spam filter, so we have high expectations for the accuracy of Clearswift's new products. More details at jgc's commercial site: www.extravalent.com.
... Richi Jennings