c:\Users\<USERID>\Application Data\Thunderbird\ProfilesWhere <USERID> is your userid. Then look for the folder called <Random Junk>.default -- that's where your precious mail is stored.
Computer Tips - Where is my Thunderbird data?
Date: 2008nov10
Updated: 2015aug18
Product: Thunderbird
Q. Where is my Thunderbird data?
A. On Windows its in:
Look in...