The standard article for moving to a new computer, or restoring to any computer, for Windows, is:

https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer#thunderbird:win10:tb68

The Linux version is:

https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer#thunderbird:linux:tb68

Basically, you copy the Thunderbird folder on the Windows computer: C:\Users\winusername\AppData\Roaming\Thunderbird

delete the contents of the .thunderbird folder in Linux, then copy the contents of the Thunderbird folder into the empty .thunderbird folder. If it were Windows to Windows, you would simply replace the TB folder on the target with the one from the source.

Do all of this with TB closed on both computers. One more thing: if you had stored passwords on the Windows computer, delete pkcs11.txt from the Linux profile folder before starting TB.

Problem not solved yet. Hi sfhowes::Please accept my apologies for not getting back with an answer. Your immediate response was very much appreciated. I lost my IP service for a few days because of a ice, snow & blizzard storm. In the meantime I've tried to follow your instructions & even practiced each step & it seems easy. I keep getting stuck by the following message; "The Inbox is too large for the destination file system". This happens when I try to download my Windows 7 Thunderbird file to any usb or external drive. I'm going to try to send a print screen copy, but if the printscreen isn't included with this, essentially the problem seems to be my Thunderbird Inbox for some reason is too large for the destination file system. I don't know how to fix this. Any help you can provide would be greatly appreciated. I use this Inbox folder everyday, so how can it be "too large for the destination file"? My Inbox folder is 28.7 GB in size. Thank you for your help.

Joyce Hansen

How is your USB or external drive formatted? If it's FAT32, which many are to be compatible with some media players, there is a 4GB file size limit. If you format the drive as NTFS, you shouldn't face any practical limits on file size.

I tried 2 different 64GB flash drives that were formatted to fat32 and it didn't work, got the message "The Inbox is too large for the destination file system". So even though 64GB should have fit it said it didn't. Being a Newbie, I thought maybe a 1TB external drive would be large enough & 28reformatted it to fat32 and got the same message "The Inbox is too large for the destination file system". I didn't know it might work with NTFS in Linux. Should I reformat the external 1TB to NTFS and see if that works? I didn't know a 28.7GB file was too large for fat32 or Thunderbird. My sister's files are much larger than that. Thanks so much for your excellent help & instructions & prompt response. So reformat to NTFS? Please let me know. Joyce Hansen

A 64GB drive or card that's FAT32 still can't store a file larger than 4GB, it just has room for 15 or 16 3.9GB files. It's the format type that matters, not the drive capacity.

Format the USB or external drive to NTFS, copy the files to the drive, and then it should be readable on any Windows or Linux compute.

https://www.howtogeek.com/235596/whats-the-difference-between-fat32-exfat-and-ntfs/

Hi sfhowes: I think I messed up my LM Thunderbird. When I pasted the Windows Thunderbird, instead of asking me to "replace data" something appeared asking if I wanted to "merge" and give a new destination (I have no idea what the destination should be. Should I uninstall and reinstall the LMThunderbird and if so how?

Reformatting the flash drive with NTFS worked great.

Here are the instructions I followed when it did not ask me to "replace data", and instead wanted me to "merge data".

From your Thunderbird profile folder, go up two levels. (I assume this meant for me to click the "top left hand corner twice and open the .thunderbird folder and click paste to make the necessary changes. Right?

Right-click inside the folder, and select Paste. This gave me "merge data" instead of "replace data". Since this didn't seem to work I thought I could just replace the LM Thunderbird Profile with the Windows Thunderbird. Think this was a big mistake on my part. Now LM Thunderbird doesn't work at all because I deleted its profile.

There is nothing, data wise I'd lose in LM Thunderbird because I never used it. How do I uninstall it, then install a new Linux Mint Thunderbird, so I can again try to move Windows Thunderbird.

Sorry I didn't get this right. I don't understand why it didn't ask me to "replace data" and must have done something wrong. Would the LM Thunderbird having an email address already have caused this? I'm at a loss and hope you can help. Thanks for all you've done for me and all the others you have helped. I wish I knew enough to help myself and others. I'm trying to learn as fast as I can and appreciate you giving back to us.

Joyce Hansen

I may have been too quick in saying to just replace the .thunderbird folder with the Thunderbird folder. The structure of the TB data is different in Linux and Windows, and different even among different types of Linux.

The profile folder in Linux is stored in this location:

http://kb.mozillazine.org/Profile_folder_-_Thunderbird#Linux_and_Unix

e.g. ~/.thunderbird/<Profile name>/

whereas on Windows it is in:

C:\Users\username\AppData\Roaming\Thunderbird\Profiles\<Profile name>

The Thunderbird folder contains a Profiles subfolder and two .ini files. The Profiles folder contains the profile folder, <Profile name>.

Linux doesn't have a Profiles folder, so all profile folders are subfolders of .thunderbird, and the two ini files from Windows should be copied into the .thunderbird folder. So, copy the contents of the Windows Profiles folder, i.e. the profile folder(s), into an empty .thunderbird folder in Linux. Copy the two .ini files, plus the other contents of the Thunderbird folder, i.e. Crash Reports, Pending Pings and registry.dat, into .thunderbird, after deleting any existing versions already there.

I suppose a quick way to do all this would be to delete the existing .thunderbird folder, replace it with the Thunderbird folder, cut the profile folders from Profiles and paste them into the Thunderbird folder, delete the empty Profiles folder, and finally rename Thunderbird to .thunderbird.

Edit: If the above still doesn't work, it's probably because the profiles.ini from Windows includes the Profiles folder in the Path definition for the profile folder. You would have to remove Profiles from the path, by editing the ini in a text editor. But the original suggestion to replace .thunderbird contents with Thunderbird contents should also work.

Hi sfhomes: Ta Da- Got it. In Thunderbird (both Linux & Windows) I just went to TB program; clicked help; Troubleshooting Information; Profile folder (opens automatically) ; copied Windows TB Profile folder to a flash drive that was formatted in NTFS, then to Linux TB program; clicked help; Troubleshooting Information; Profile folder; (opens automatically) and followed your newest instructions below: " Linux doesn't have a Profiles folder, so all profile folders are subfolders of .thunderbird, and the two ini files from Windows should be copied into the .thunderbird folder. So, copy the contents of the Windows Profiles folder, i.e. the profile folder(s), into an empty .thunderbird folder in Linux. Copy the two .ini files, plus the other contents of the Thunderbird folder, i.e. Crash Reports, Pending Pings and registry.dat, into .thunderbird, after deleting any existing versions already there." My TB didn't have a ".dat" file but everything migrated perfectly.

The only thing weird that happened was I no longer have a wireless connection. Don't know why. Guess I can hopefully get help with that on this forum, right? I've never done a wireless connection before. Don't know if forums would know, my IP provider or where to the information but it looks like the IP provider would give me the data input and the forum could tell me how/where to type the provided data to get my wireless working again. Is that correct?

Again, thank you so very, very much for all this help with my TB Windows to Linux migration. You and Linux have been a wonderful experience.

This forum isn't really the place to ask about wireless networking, but there should be plenty of online help for Linux, such as:

https://www.reallinuxuser.com/how-to-setup-wifi-in-linux-mint/

Hi sfhowes: I don't see where to mark that "migration from windows to linux for thunderbird" problem is solved. It's solved. As for my wireless router not being seen by my Dell 5500 Latitude computer, I'll check the link you sent me further and onine.

Thank you again for all your help and sharing your knowledge with me and all the others who will benefit from this post.

Joyce Hansen

Glad to hear you've got the migration issue fixed. The reply I made on 1/27 2:11 PM has already been marked as 'Chosen Solution', either by you or a forum moderator, so I guess that option doesn't appear on this page after it's been selected.

hi all, sorry to barge into this thread, but for me all the above described procedures didn't work. i tried to move my windows profile (windows 10 home edition) to ubuntu 18.04.4 LTS and also kept in mind the different folder structure of ubuntu (i even adjusted the "installs.ini" and "profiles.ini" likewise), i even uninstalled tb and re-installed it again, but it just won't work. all i get is the information described under "unable launch older version on profile". so i tried to convince tb to work with multiple profiles, following the instructions given there, but it's still the same - "unable launch older version on profile". i'm totally stuck now, and i'm clueless...

toru_ said

hi all, sorry to barge into this thread, but for me all the above described procedures didn't work.

When you copy a profile from one computer to another, even when the TB version is the same 68.* on both computers, you may see the error shown in the attached picture. In that case, click Exit and start TB Profile Manager: http://kb.mozillazine.org/Profile_manager#Linux then select the copied profile, OK. If that still doesn't work, launch Profile Manager but add to the command line --allow-downgrade

to put it in a nutshell - "--allow-downgrade" did the trick. yesss!

nothing else had worked eventhough both versions were 68.4... but this simple line solved the problem. thanks a lot!

another bug... sigh.

now that TB finds all my old emails (as well as the addresses), i noticed that it isn't able to keep passwords anymore. and when i look up the password manager, it's empty. blank. whatsoever.

first when TB asked me to put in all the account's passwords, i thought "okay, after the migration it needs the passwords again", but it's weird that TB needs the passwords now every single time i check my emails (and i got a lot of accounts - that's why i use TB).

additionally, TB now doesn't seem to get any new emails, although there are at least some new mails in the meantime. so i unistalled TB, installed it again, allowed the downgrade - and got the same problem again...

- is there any file i can check, or any preference/setting?

- ...and does it matter that all accounts use the same inbox?

- if this all doesn't work so that i have to create a completely new profile - is there a possibility to copy single emails from the old profile into the new one (so that they can be read again)? on the long run, i'd like to switch to ubuntu permanently (at least that was my plan), so it would be great to "save" at least the most important emails from the old profile...

Did you delete the pkcs11.txt file from the profile folder? That is often the reason passwords aren't read after a Windows to Linux copy. To delete all password data, delete logins.json, cert9.db and key4.db. These files will be automatically recreated when TB restarts, but you will have to enter account passwords when prompted.

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

Transferring data from one profile to another is fairly easy, although mail is stored as one (mbox) file per folder.

...deleting the pkcs11.txt file made it work again. TB-ubuntu receives emails again. THANKS!