“Originally, the GMail Loader only worked with mBox format files (because it is all I needed) and was command line based. As others asked for similar functions, I began to expand it. Today, the GMail Loader is a graphical, cross-platform, Python based utility that supports two mBox formats (Netscape, Mozilla, Thunderbird, Most Other Clients), MailDir (Qmail, others), MMDF (Mutt), MH (NMH), and Babyl (Emacs RMAIL). Eventually, I plan to add support for direct sending of IMAP accounts, and am working on a library that can read and export Microsoft Outlook PST files.”
M. Lyon via Janne