Importing from Outlook in Thunderbird 38 and never versions has been broken for a long time. I haven't tried it in version 102 yet, and have no idea if things are still broken in that regard. In our KB article here https://support.mozilla.org/en-US/kb/switching-thunderbird#w_importing-from-outlook-and-eudora, Thunderbird version 31.8 is recommended for the import, and then you can upgrade to Thunderbird 102 after successful import. This means you need to uninstall Thunderbird 102, install Thunderbird 31.8, do the import, then manually download and install never versions of Thunderbird until you're up to date with version 102.

If this seems like too much work, you can alternatively use a free email archiving solution known as MailStore Home as an intermediary tool, to import Outlook mail into MailStore, then export the same from MailStore straight to Thunderbird 102.

Thank you very much Stans! I will try the software option MailStore Home, as it seems the friendliest way to do this. And also for future migrations. I'll reply and solve if it works.

import using a 32 bit version of V102 should work. I have just been working with someone else in recent days importing from an old version of outlook and his import started working when the 32bit outlook and the 32bit Thunderbird got together to import.

Thank you Matt. I have everything 64-bit, so I'll continue with the MailStore, though it isn't clear if I can make use of it yet. If not, I shall try going 32-bit.

I looked at the code, and I have a sneaking suspicion that it is only going to work for 32 bit. But my C++ is at best quite basic. I would still suggest trying the 32bit option. If for no other reason than informing me if I am on the right track. These imports are problematical and I really think the bitness of the application has something to do with it.

You have proved 2 64bits do not work. I know two 32bit do work from previous support issues. What I do not know is is a 32bit Thunderbird will import from a 64bit outlook.

Once I can actually make some sort of sense of what does and does not work. Then I can make waves. But right now I am just another guy with a theory. At the very least I can document what does and does not work for the next "you" that comes along here.

Hello Stans, Matt, I have now found the MailStoreHome to work sufficiently for my purposes, i.e. migrating Outlook mail to Thunderbird mail in Windows, and from Thunderbird Windows to Thunderbird Linux, which was my intention all along. I am migrating our PC's from Windows to Linux. But everything takes a heck of a lot of time. I thank you for your support, and will now resolve this question. Linux and Mozilla is our future, in this family anway.

Linux and Mozilla is our future, in this family anway.

Not in mine. My wife is welded on to Microsoft office. Periodically I also find myself using it when developing macros for Microsoft Office work sites. I must say I still prefer to develop in Office/Windows than in say LibreOffice/Linux. Microsoft have many faults. Making things pretty and easy to use even if you have no idea is not one of them and VB is still a very simple way to get powerful things done.

Outlook however has always been a pig of a mail client for non exchange functions. If it is paired with Microsoft Exchange for which it was originally written it becomes an exemplary choice for a corporate mail system. It is only familiarity that sees folk use it at home where it is actually a relatively poor fit.

Sorry I got on my high horse there. I wish you luck in your endeavor to go open source.

Hello Stans, Matt, I have now found the MailStoreHome to work sufficiently for my purposes, i.e. migrating Outlook mail to Thunderbird mail in Windows, and from Thunderbird Windows to Thunderbird Linux, which was my intention all along. I am migrating our PC's from Windows to Linux. But everything takes a heck of a lot of time. I thank you for your support, and will now resolve this question. Linux and Mozilla is our future, in this family anway.

Will you share (if you recall) what specific steps you took after downloading & installing MailStoreHome? After I install the app should I go to Export and then create a profile for Outlook? Then what? I've checked around Google a bit looking for an answer to this. No joy. I've been stabbing at it for a few hours now.

Thank you in advance!

Hello n10s: I cannot recall exactly what I did, and now I don't have MailStoreHome either, as it was only for Windows, and I am now totally Linux, not even dual-boot. But I recall some problems needed solving: large amounts og mails must be split into several parts to be handled; Calendar must also be split into several parts in order to work. And it all hinges on the Profile bit, this is where you save your Win Outlook mails and from there you export the saved profile data. At last you should be able to import it into Linux Thunderbird. But a realtime recipe from me is not possible now. Just keep plugging, try everything, and at last you will succeed. Regards HCE

Hello n10s: I cannot recall exactly what I did, and now I don't have MailStoreHome either, as it was only for Windows, and I am now totally Linux, not even dual-boot. But I recall some problems needed solving: large amounts og mails must be split into several parts to be handled; Calendar must also be split into several parts in order to work. And it all hinges on the Profile bit, this is where you save your Win Outlook mails and from there you export the saved profile data. At last you should be able to import it into Linux Thunderbird. But a realtime recipe from me is not possible now. Just keep plugging, try everything, and at last you will succeed. Regards HCE

Thanks, a bunch! Plowing through as winners do! Regards.

Thanks, a bunch! Plowing through as winners do! Regards.

See https://help.mailstore.com/en/home/Archiving_Email#Archive_from_Microsoft_Outlook.2C_Windows_Mail_or_Windows_Live_Mail and https://help.mailstore.com/en/home/Exporting_Email in that order.

Help for Mailstore is available here https://help.mailstore.com/en/home/MailStore_Home_Help and its support community as well, linked to on that same page.

Hello again n10s, I just remembered an important point, a shortcut: when you have a good working version of Windows Thunderbird, you can actually just copy the relevant contents of the subfolders from Windows Thunderbird to Linux Thunderbird. These subfolders are: abook.sqlite, calendar-data/local.sqlite, Mail/post.xxxx.