Move Thunderbird data to a new computer

Thunderbird stores your data in a separate location, away from the program filesapplication, called your profile folder. To move your data, you can copy your profile folder to the equivalent location on your destination computer. Ensure both versions of Thunderbird are up to date or identical before attempting a transfer as otherwise it might fail.

• On your source computer
  1. Connect a device for data transfer, either a local one such as a USB flash drive, or a remote storage drive.
  2. Click the menu button , then click Help and select Troubleshooting Information.Open the Help menu and select Troubleshooting Information.
  3. Locate the "Profile Folder" entry, then click Open FolderOpen DirectoryShow in Finder.
     Your Thunderbird profile folder will open in Windows ExplorerFile BrowserFinder.
  4. CloseQuit Thunderbird.
  5. From your Thunderbird profile folder in Windows ExplorerFile BrowserFinder, go up three levelsgo up two levelsopen the Go menu and select Enclosing Folder two times.
  6. Right-clickHold down the Control key while you click on the Thunderbird.thunderbird folder and select CopyCopy "Thunderbird".
     (.thunderbird is a hidden folder. Make sure you have File Browser set to show hidden files.)
  7. Right-clickHold down the Control key while you click the device you are using to transfer your data, then select PastePaste Item.
  8. If you are using a local transfer device, remove it safely from the source computer.

• On your destination computer
  1. Connect the same transfer device you have used before to copy your Thunderbird profile folder from the source computer.
  2. Right-clickHold down the Control key while you click on the copy of the Thunderbird profile folder that you created on the transfer device, then select CopyCopy "Thunderbird".
  3. Open Thunderbird (Close the account setup window if it appears.)
  4. Click the menu button , then click Help and select Troubleshooting Information.Open the Help menu and select Troubleshooting Information.
  5. Locate the "Profile Folder" entry, then click Open FolderOpen DirectoryShow in Finder.
     Your Thunderbird profile folder will open in Windows ExplorerFile BrowserFinder.
  6. CloseQuit Thunderbird.
  7. From your Thunderbird profile folder in Windows ExplorerFile BrowserFinder, go up three levelsgo up two levelsopen the Go menu and select Enclosing Folder two times.
  8. Right-clickHold down the Control key while you click inside the folder, then select PastePaste Item.
  9. When prompted, choose to replace your current data.

• An alternative method:
  1. Hold down the Option key while pulling down "Go" on the Mac's main menu. Select and open Library.
  2. Within the Library is a Thunderbird folder, which can be copied/pasted or Shared (ie. right-click, Share, AirDrop if the receiving computer is in close proximity)
  3. Ensure you already have the Thunderbird app installed on your receiving computer, but don't open it to check messages. Go through the same process (Option key, Go, Library) and replace the empty (or old) Thunderbird folder on the receiving computer with the existing Thunderbird folder that contains all your current data.
  4. Test Thunderbird on the receiving computer - it should look identical to your original on the sending computer and contain all the same messages. CAUTION: Do not open Thunderbird again on the original computer - unless you repeat the process in reverse to transfer the folder contents back to the original computer before opening the app. (If you forget, you can manually check one version against the other to ensure important messages are retained, but it's messy and time consuming.)
• Another alternative method: For manual transfer between Windows 10 and Windows 11 Computers
  1. This section assumes you have a default Windows installation and will work on computers upgraded to Windows 10 from previous Windows versions
  2. Locate the master profile folder on the source computer as above.
  3. Locate the master profile folder on the destinition computer as above.
  4. Note out of interest that your user name ( indicated by ~ below) on the two computers might be different due to legacy issues but it will make no difference with a manual transfer as below.
  5. Close Thunderbird in both computers.
  6. Copy the Thunderbird folders in both Windows(C:)/Users/~/AppData/Roaming and Windows(C:)/Users/~/Appdata/Local on the source computer to your transfer media in separate folders so you do not over write them
  7. Remove or Rename (if you need a data backup or to preserve old profile) on the destination computer any Thunderbird folders in the destination folders Windows(C:)/Users/~/AppData/Roaming and Windows(C:)/Users/~/Appdata/Local directories
  8. Copy from your transfer media the correct Thunderbird folders into the two folders to replace the ones you have removed/renamed
  9. Restart Thunderbird on the destination computer and test it, noting that your inbox tab should be identical to source but that other tabs may have opened with Thunderbird messages.