Locate the Thunderbird Profile
You may never need it to restore it, but it is a good idea to make a backup profile from time to time, just in case. When you want to restore your Mozilla Thunderbird data from a backup copy, the process is simple.
Before you can replace it with a backup profile, you need to find the existing profile on your Windows or Mac computer. To locate it:
Open Thunderbird. Select Help on the menu bar. Select Troubleshooting Information. In the Application Basics section, next to Profile Folder click Show in Finder, which takes you to the profile folder on your computer.
If you have never moved your profile folder, you can opt to go directly to the profile folder in Windows 10, 8.1, 7, and Vista using this path: C:\Users\AppData\Roaming\Thunderbird\Profiles\
The direct path on a Mac running OS X or macOS is ~/Library/Thunderbird/Profiles//
However you get there, you’ll see a folder with a six-random-character name and a .default extension.
Restore a Mozilla Thunderbird Profile From a Backup Copy
To restore your Mozilla Thunderbird Profile from a backup:
After you’ve located the existing Thunderbird profile, quit Thunderbird. Confirm that the existing profile folder and the profile backup have identical names. If your backup profile uses the . Restoration Profile extension, change it to the . default extension. Replace the existing profile with the backup file.
