From Weird Kid Software:
Emailchemy converts email from the closed, proprietary file formats of the most popular email applications to standard, portable formats that any application can use. These standard formats are ideal for long term archival, database entry, or forensic analysis and eDiscovery. Emailchemy includes an embedded IMAP mail server from which any IMAP-compatible email application can import your converted email. Emailchemy also includes a utility for uploading converted mail up to a Google Apps email account. Emailchemy provides utilities for splitting, sorting and merging email archives, and harvesting email addresses from email archives. Emailchemy can readAOL for Windows ("PFC" files), Claris Emailer, CompuServe Classic for Mac, CompuServe 2000 for Windows, Entourage, Eudora, Mac OS X Mail, Mozilla, Mulberry, Musashi, Neoplanet, Netscape, Opera, Outlook for Windows, Outlook Express, PowerTalk/AOCE for Mac, QuickMail Pro, Thunderbird, Yahoo Mail, and any mbox-format.
What's new in this version:
Version 12.0 includes full native support of Outlook for Mac 2011 databases, de-duplication of messages, IMAP import compatible with Outlook 2013, "Headers only" output option, and user interface improvements.