POP accounts only download the Inbox and cannot subscribe to any folders. IMAP is the only way to see those folders in TB or any other mail app.

Hi sfhowes! Thank you for your reply!

I do not want to use this laggy, useless and problematic IMAP protocol...

I want all of my e-mails and my attachments to be stored in my computer and to be able to search them or download them, even if I am offline.

I read somewhere that in the past there was a plugin for Thunderbird which enabled you with this feature (to download - and I think, to synchronize - other folders, like Sent messages of your web account's mailbox, etc.).

Is there really such a plugin?

These folders:

a) 2015-2020 b) 2021-2023

has static information inside them (I do not move new e-mails there or remove e-mails from there) and I have them as an archive.

Your choice is IMAP or POP and there is an addon for Microsoft Exchange

IMAP is no slower on most occasions that POP once the initial syncronisation of the folders and mail occurs. At least it is not slower for those of us that do not use antivirus programs that scan incoming mail and reduce the speed of downloads to about 50% of normal in their process.

OK, so maybe I just don't like it (IMAP), or it doesn't fit to me and my job.

Therefore, what solution do you suggest for POP3?

Given the fact that these folders:

a) 2015-2020 b) 2021-2023

has static information inside them (I do not move new e-mails there or remove e-mails from there) and I have them just as an archive (to read them only)?

I have already downloaded my whole Mailbox from Outlook.com as a PST file (by clicking to the "Export mailbox" button in Settings -> General -> Privacy and data).

So, is there a way to import these "2015-2020" and "2021-2023" folders to Thunderbird from PST?

The simplest solution that I would offer is to create an IMAP account alongside the POP account, download the two folders with file>offline>sync, copy the two folders to local folders, and then remove the IMAP account.

Very helpful david!

But instead of this, because these folders are about 20GB, is there a way to import them through the PST I already have in my hands?

Can I import these folders from the PST to the local folders? And, if the answer is yes, how can I import anything to the local folders?

To me, that seems a lot of work, but it's doable. I am no PST guru, but if you do a web search for 'thunderbird pst import' there are many websites with step-by-step instructions. Good luck.

I think you can import pst files to MailStore Home, and either keep them there as an archive, or export them to eml or mbox format from MSH, which can then be easily imported to TB Local Folders.

Very helpful david! But instead of this, because these folders are about 20GB, is there a way to import them through the PST I already have in my hands? Can I import these folders from the PST to the local folders?

Yes, load the PST into Outlook and then use the importer in Thunderbird to import from Outlook. Or just run the importer from the tools menu on your existing outlook installation.

What Thunderbird can do it talk to outlook, it can not do anything at all with a PST file.

And, if the answer is yes, how can I import anything to the local folders?

You are holding a proprietary formatted file. While Microsoft have published a number of descriptions of the file formats used in various versions of the PST over the years, Thunderbird has never been able to read any of those formats. There has never been a commitment of sufficient resources to write import code for that file format as there is functional code for the import from Outlook. This is even less important as most folk now use IMAP and the data is generally available from the web unless the person is already using a desktop mail client like outlook.

The internet is essentially full of converters to convert PST files into mbox files (google is your friend here) which Thunderbird uses natively. They vary in cost and quality and as I am not at all involved with using any of them I can not offer advice as to one over another.

Once your data is in a non proprietary format you can either place the files in the local folders directory in Thunderbird profile (without a file extension) or use the import export tools add-on to import the mbox files for you. https://addons.thunderbird.net/en-US/thunderbird/addon/importexporttools-ng/?src=ss

As sfhowes says mailstore home may read these files, but it is not Thunderbird. It is also a windows only solution (so no access from your Android or Apple phone) to email archiving that is free for home use. I mention the license requirement for free home use only as you mention your requirement include your job which to me implies bushiness use.

Hi all! Thank you, Matt!

Sorry for the delay in my reply, I don't know if you've heard of us here in central Greece, we had very difficult times the last week with very big floods, disasters, power outages and water outages for several days... (a brief review here: https://edition.cnn.com/2023/09/07/europe/greece-floods-storm-rescue-climate-intl/index.html )

So,

I opened Microsoft Outlook 365 (Ver. 2308 - Build 16.0.16731.20052 - 64 bit) in my PC (Windows 11) and I went to New Items -> More Items -> Outlook Data File. I created here a PST data file. Then I went to File -> Open & Export -> Import/Export and I imported from here the contents from one folder only of my big PST file (folder “2015-2020” with 14.043 mails inside it). Outlook imported only 512 emails from PST and then gave me the Warning: “Some items cannot be copied. They were either moved or deleted, or access was denied.”. So, I searched Google, I run the SCANPST.EXE, it found some (strange) problems and it supposed that fixed them, but again the results are the same!

I’ve also changed the access permissions of my big PST file, I added “Everyone” with full access permissions, I’ve changed also the owner to “Everyone”, added principal “Everyone” with full control, I also added “Everyone” to Auditing with full control too, but the Warning remains with the importing.

Then I searched Google again for solutions and I found a Windows app called “Esofttools - Outlook PST Recovery” which promises that can fix the PST and, also, to convert it to MBOX file. But I have never heard about Esofttools, I don’t know if it is trustworthy or some kind of scam/malware.

Therefore!!

Before I continue with this way (please, if you have any tips about the import, the warning or the app, feel free to post them), I decided to try the david’s solution, to “create an IMAP account alongside the POP account, download the two folders with file>offline>sync, copy the two folders to local folders, and then remove the IMAP account.”.

Βut what concerns me with this way, is, are all my messages (with their attachments) going to be downloaded in full or not?!

Thanks!!

@Matt and @Sfhowes have technical knowledge far above mine. My approach is to just do it and verify samples throughout. I have never lost mail with Thunderbird. And doing this doesn't preclude the other approaches if you're not satisfied.

So!

Anyone?

About my concern, using IMAP just to copy my e-mails form my two folders ("2015-2020" and "2021-2023"), are all my messages (with their attachments) going to be downloaded in full and will I be able to have them all available offline or not?!

Do you propose me to follow this method (@david's method with IMAP)?

Or, do you have a solution for importing my PST?

Regards, george.

I admit to being puzzled. Why not just "do it" to see if it works, instead of just contemplating the action? PST conversions are not a specialty here.

I admit to being puzzled. Why not just "do it" to see if it works, instead of just contemplating the action? PST conversions are not a specialty here.

Because I will never be sure that every e-mail and it's attachment inside these folders will have been fully downloaded in the folder and will be available 24/7 for offline use!

By testing them randomly, some maybe working fine (maybe are loading instantaneously over the internet and not from the local MBOX)...

I have about 30.000 E-Mails there, I cannot test them all of course...

Regards, george.

My perception is that there is risk in any approach you take, and no one here can assure you of an error-free path. Every suggested approach (as I understand them) requires moving those 30,000 messages from one platform to another. You could do several different strategies and then compare results to determine the approach that seemed to work best. At this point, the issue is yours, George. I wish you well.