Saving your Thunderbird can be helpful to store settings information and downloaded mail.
To save your Thunderbird profile, perform the following steps:
1. Open Thunderbird and empty your Trash and Junk folders for all of your email accounts.
2. When you’re done, close Thunderbird.
3. Open Terminal.app
4. cd Library/Thunderbird/Profiles
5. You should see a profile or possibly multiple profiles. The directory name is XXXXXXXX.default where XXXXXXXX is a random string of letters and numbers. Ex. aunnx2xs.default
6. tar -czvf /path/to/save/file.tar.gz XXXXXXXX.default
where XXXXXXXX should be replaced with the correct directory name.
Ex. tar -czvf /path/to/save/file.tar.gz aunnx2xs.default
7. When the tar is complete, you can restart Thunderbird.
NOTE: This tarball can be used to set up the profile on another Mac. To do so, you can scp, ftp, or use a thumb drive to transfer the data to another mahcine. When you’re on the other machine, you can open Terminal.app and cd to Library/Thunderbird/Profiles. Next, tar -zxvf /path/to/save/file.tar.gz. It will extract the files to the appropriate directory.