I need to clarify what you mean by 'reinstalling'. Was this an installation on a different machine? Did you 'overwrite' an existing installation? Did you uninstall and install on the same machine? Did you make a back up of your profile folders and data files?

I uninstalled and installed on the same machine and didn't make a back up myself. I hope maybe thunderbird does something like that by default and its support has those e-mails somewhere in their database.

In future, make back ups weekly. It saves a lot of heartache when systems crash.

In Windows, your profiles and data files are at C:\Users\[Users]\AppData\Roaming\Thunderbird\Profiles\XXXX.default-release

For TB to have kept an old copy of your files, it would need to have been made in 'Profiles' (there is a .default' folder but this isn't a previous Profile). My guess is that there might be a third folder in here with your old data.

If it's not, please reply to this and your email will go back in the queue for someone else to look at.

Thank you, but could you give me instruction for MacBook? TB is installed there

Thank you, but could you give me instruction for MacBook? TB is installed there

Nope. Sorry. I have never used a Mac. It will be where the Mac stores the Data files for your programs.