I occasionally run into this issue whenever I switch OSes. If you happen to use a dual boot between Linux and Windows you might find yourself in a similar situation. You may be tempted to switch mail clients but Mozilla’s Thunderbird remains one of the best, even if it does feel a bit neglected from time to time.

For some people, using an online mail provider like Gmail/G Suite or Zoho Mail might be an option as well. They can have vastly improved delivery rates and improved spam protection and a host of other features integrated. They have free and premium services alike. Although some people will be rightfully concerned about security and the drawbacks of storing their mail and whatnot with an online service, it can make things a lot easier and better for some so this is why I’ve mentioned them.

As you may already know, you can copy the Thunderbird Profile folder to migrate everything into Linux. However sometimes things don’t go completely smoothly. It’s a generally unsupported process but there is hope. It will work!

I’ve tried using extensions to export and import them to no avail. What does work is shown below.

  1. First of course copy your folder. If you’ve already done this you may want to copy a fresh one if you’ve messed with things too much. You made a backup, right?
  2. Then open the prefs.json file and replace all the paths to your new profile location. We aren’t done with this file yet.
  3. Also delete all lines in the prefs.json file that start with user_pref("extensions..
  4. Now go through the files listed as safe to delete or that might solve issues by deleting them and then try to start it again. This includes pkcs11.txt which might be the culprit if you can’t save your passwords in the password manager properly after doing all the other things.

    Here is a complete list of files I deleted, some were probably form much older versions of Thunderbird:
    • pkcs11.txt
    • localstore.rdf
    • mimeTypes.rdf
    • global-messages-db.sqlite
    • key3.db
    • cert8.db
    • extensions.sqlite-journal
    • extensions.sqlite
    • extensions.json
    • extension-preferences.json
    • compatibility.ini
    • xulstore.json
    • panacea.dat
    • extensions/
  5. You should delete some extensions related files and the extensions folder to get rid of those too. And of course delete the lines mentioned in step 3 above. The necessary things will be regenerated when you start Thunderbird.

That seems to be what’s worked for me to move Thunderbird from Windows to Linux. I just wanted to make a note of it for next time I run into this issue. Hopefully it helps someone else.

Here are some useful links:

https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer

http://kb.mozillazine.org/Prefs.js_file

http://kb.mozillazine.org/Files_and_folders_in_the_profile_-_Thunderbird

http://kb.mozillazine.org/Moving_from_Windows_to_Linux

http://kb.mozillazine.org/Moving_your_profile_folder

http://kb.mozillazine.org/Profiles.ini_file