All that space and nothing to put in it… Mark Lyon has put together an import utility that will import your mail from an existing mail program that utilizes the mbox or maildir format. Typical programs that utilize the mbox format are Netscape, Mozilla, Pocomail, etc. Maildir is more typically found being used in Unix. Mark has graciously provided a packaged python script for Windows (all you need is the downloaded file he provides). He also provides the Python source for use on Unix and other operating systems.

Operating System: Windows, Unix, other OSes with Python

Source: MarkLyon.org