Thanks for mentioning POPFile, good to hear my old code mentioned on Hacker News. I wrote the original code for POPFile in Visual Basic(!) in 2001 (it was called AutoFile back then) as I wrote it initially for my own use without Microsoft Outlook. I got the idea of using Naive Bayes for my email classification after seeing the ifile extension to exmh(1). ifile dates to 1996.<p>I rewrote POPFile in Perl and made it work with generic POP3 servers (hence the name) and later with IMAP and more. It is still actively maintained by a group of people I&#x27;ve never met(!) with the last release in December: <a href="http:&#x2F;&#x2F;getpopfile.org&#x2F;" rel="nofollow">http:&#x2F;&#x2F;getpopfile.org&#x2F;</a><p>(1) <a href="http:&#x2F;&#x2F;qwone.com&#x2F;~jason&#x2F;papers&#x2F;ifile00.pdf" rel="nofollow">http:&#x2F;&#x2F;qwone.com&#x2F;~jason&#x2F;papers&#x2F;ifile00.pdf</a>