I am a great fan of the email client Thunderbird. I have used Mozbackup to back up my emails whilst doing a windows restore.
Due to the fact that I did not import my emails into my email client (because I did not know how to!!) I did another backup with MB only to find I now have 2 files ]
If I import my emails the ones already in are overwritten by the new ones.
How can I join me emails together?