Spot Documents says their Mac OS X application for archiving Apple Mail on OS X is now free for a limited time at the Mac App Store in the Business category. It’s normally US$9.99.
Email Archiver (http://www.spotdocuments.com/emailarchiverapp/) is a tool for Mac experts, sysadmins, or superusers. It creates a permanent, archival quality set of PDFs, one for each email on a computer. The software works with Apple’s Mail, storing emails as PDFs. It makes them compatible anywhere a PDF works, not just with Mail.app.
The folks at Spot Documents say that by giving the application away free for a limited period of time the company hopes to gain mindshare among the OS X community. Email Archiver requires Mac OS X 10.6.6 or later.