I have installed the Thunderbird email client and think that the mails are being stored in the files Inbox and Inbox.msf. Is it possible to convert the Inbox and Inbox.msf files into individual files?
You can install and use "ImportExportTools" Thunderbird extension (add on). You can mass-export email folders in individual eml files or other. See detailed info in http://www.nic-nac-project.de/~kaosmos/mboximport-en.html
If you need to export your folders in other email client, details are in http://kb.mozillazine.org/Importing_and_exporting_your_mail