You need to explain what format your messages are actually in. First you mention that the mail files are binary, then you state that the files are in "mail format". To me, "mail format" implies Unix mbox format which is a simple text-based format to store mail on a Unix system. What program created these files? Outlook or Outlook Express? Try looking on CPAN for Outlook. If you tell us what mail program created these files, we could be more help.

HTH