This script splits raw email folder backup files into to single email files which you can then import using a tool like ImportExportTools (https://addons.mozilla.org/de/thunderbird/addon/importexporttools/)
By default this script expects backups in the subdirectory backup and saves the converted emails to converted. Both directories must exist. Default charset is ANSI. Edit converter.py to change any of these defaults.
Just run converter.py using python, i.e. python converter.py from commandline.