I want to migrate/copy my Thunderbird from Windows 7 to Ubuntu, where I already set up another Thunderbird installation with some old and also some new accounts. To save me more configuration work, is it possible to just merge/synchronize the account settings and address books, so that the one on Ubuntu contains everything?

I have read access to the drive where Windows-Thunderbird is installed. However, I can't just copy old files and replace my current ones, as there are already other, new accounts set up I also need to keep.

Note that many of the accounts are POP3, so mails are saved on the disk, not in the cloud. I should copy them over too.

So in short: How do I merge and synchronize accounts created with Thunderbird easily?

  • You can either merge the text based files together then copy the emails to the apppropriate folder? – Ramhound Jul 1 '15 at 18:31
  • I reworded my question to make it more clear. – Byte Commander Jul 1 '15 at 18:41
  • @Ramhound Could you go a bit more into detail please? Which files? Can I just append one to the other? What settings/data can I merge this way, where do I need another method? – Byte Commander Jul 1 '15 at 18:42
  • I have not used Thunderbird in years, stopped because of the incredible amount of work it takes, to export emails from Thunderbird. Your account settings are text files are they not? You should be able to merge the two files together ( keeping a backup of the originals ) and then manually transfer the existing physical .eml files over. – Ramhound Jul 1 '15 at 19:06
  • @Ramhound And which file would that be? I can't find any file that is obviously named... Especially none of the plain-text files. – Byte Commander Jul 1 '15 at 19:23

The account details are all stored in the configuration data, which are saved in the text file prefs.js in the profile directory, so you can import parts of this from one system to another.

The relevant settings are the mail.account... and the mail.server... entries, but it is not as straightforward as copying and pasting.

  • You first need to extract the server settings (mail.server...) from the system where they are defined.
  • You then need to offset the sequence numbers so that they continue the sequence in the target system.
  • You can now merge the entries into the target prefs.js.
  • You next need to add mail.account.accountNN entries for the imported accounts.
  • If there were mail.account.accountNN.identities in the source prefs.js, then both they and the corresponding mail.identity.id... entries will need to be extracted, renumbered and merged.
  • You will need to add the new accounts to the mail.accountmanager.accounts entry and update mail.account.lastKey.

I think that is all that needs doing. Whether it is less work than entering the new accounts by hand will depend on the number involved.

I hope it goes without saying that both prefs.js files should be backed up first, and that Thunderbird should not be running while the files are being modified.

  • Thanks, this looks ok. I will try it, but I fear reentering all data is probably still easier and faster than this... :-/ – Byte Commander Jul 3 '15 at 6:59

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.