Why can't I see import Mbox options

[Colins2]

There are no menu items to import Mbox files as per the screenshot.

[cleidigh]

@Colins2
I can't see the folder you are attempting to import to, but I suspect it is an imap folder. Because of sync issues where servers, even google, get swamped or throttle traffic, mbox import to imap folders is not permitted. Import to a local folder.
@cleidigh

[Colins2]

@cleidigh Thanks for the reply.
I wasn't aware that I needed to also have the Local Folders add-on installed. Once I installed it and created a local folder I saw the menu items.
The import works sometimes. What I mean by that is that some folders import others do not. I think it is due to nested folders that I exported from my Gmail account. I have found that I can import the failed folder as a single item and it seems to work.
Some emails open up and all I get is the title, no content or if it is part of a 'conversation' then I get multiple tabs open with the titles but no content? I suspect this may be a Thunderbird problem though.
From the import mbox menu items I have tried all the options with mixed success. I think I will start over with a new install of Thunderbird and import each mbox file one by one. The files are OK as I can read them with mutt but that is obviously not as convenient as having them in Thunderbird.
Where is the sub-folder information stored? Is it coded in the actual mbox file? Could Thunderbird not showing content be because I have imported them to a main folder and not a sub folder?
Thanks for the add-ons, anyway, they are very useful.

[cleidigh]

@Colins2
I think there may have been some confusion . ImportExportTools does not require my LocalFolders addon to import mbox files. What I was referring to was the pseudo account called "Local Folders" which is created when you create an email account. This allows you to have email folders stored locally on your pc. If you didn't see this, something went wrong in your account creation. My LocalFolders addon allows you to create extra Local folder accounts.

I'm not sure what a structured Google takeout looks like. All my takeouts were single mbox files. I've done plenty of testing with those as have others, it's pretty solid. The only structured subfolders ImportExportTools understands is Thunderbird's sbd structure (something I need to improve on), so other than that it cannot import a structure. The mbox files themselves carry no structure, they are just a collection of RFC822 emails.

The emails from Google should import fine, so I'm not sure what you are seeing. I am suspicious about you not having the standard Local Folders account so maybe starting over makes sense.
@cleidigh

[Colins2]

Hi Chris, My initial setup may indeed be the problem then. When asked to create an email account, I declined that as I only wanted to have a readable archive of my old emails. I have switched to ProtonMail as my main client now. I requested a takeout package from Google up to a certain date with ProtonMail taking over from then. As I had a Gmail account since 2005 or so, there was a lot to download and the data came in 3 large archive files. Opening the archive zip files just reveals a list of mbox files with any nested folders simply presented as separate files with no info on subfolders or anything like that. If you don't create an email account in Thunderbird then there is no local folder so after some searching I found your other add-on to create a local folder. As far as the mbox files import, I have found that importing the whole folder doesn't work. Some mbox files get imported and are readable but others simply create the folder that remains empty. However, that same file will import if I do it as a single file. Of the 4 options on the import mbox menu, only the "Individual mbox files (with sbd structure) works as expected. The individual mbox files option just creates an empty folder. I think that my problems are somehow sub-folder related. If I try and import all the mails from the archive file, the single entries seem to be OK but the folders with subfolders do not import. What was baffling me is that they just appear to be regular mbox files that I can view with mutt. I assumed that the nested folder structure was just something implemented in Gmail's client. One final point is that I can create folders and sub folders with your LocalFolders tool but I can't delete them. I tried a couple of times to use the 'individual mbox files' option, without the sbd option and ended up with empty folders that I can't get rid of. So, in those cases, I imported the mbox files with the sbd option as sub-folders and that worked. So, I'm getting my archive imported thanks to your extensions and it is actually working out better as I need only import the mbox files that I will reference. The others just remain in the Google archive. I really appreciate the work that you have done to make this possible. Kind regards Colin Sare-Soar Sent with [Proton Mail](https://proton.me/mail/home) secure email.

…

On Monday, December 1st, 2025 at 03:27, Christopher Leidigh ***@***.***> wrote: cleidigh left a comment [(thunderbird/import-export-tools-ng#825)](#825 (comment)) ***@***.***(https://github.com/Colins2) I think there may have been some confusion . ImportExportTools does not require my LocalFolders addon to import mbox files. What I was referring to was the pseudo account called "Local Folders" which is created when you create an email account. This allows you to have email folders stored locally on your pc. If you didn't see this, something went wrong in your account creation. My LocalFolders addon allows you to create extra Local folder accounts. I'm not sure what a structured Google takeout looks like. All my takeouts were single mbox files. I've done plenty of testing with those as have others, it's pretty solid. The only structured subfolders ImportExportTools understands is Thunderbird's sbd structure (something I need to improve on), so other than that it cannot import a structure. The mbox files themselves carry no structure, they are just a collection of RFC822 emails. The emails from Google should import fine, so I'm not sure what you are seeing. I am suspicious about you not having the standard Local Folders account so maybe starting over makes sense. ***@***.***(https://github.com/cleidigh) — Reply to this email directly, [view it on GitHub](#825 (comment)), or [unsubscribe](https://github.com/notifications/unsubscribe-auth/AJQF55N5QIRGLATEI5W7DSL37NHKHAVCNFSM6AAAAACNPGPTFGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTKOJTGMYDCMZYGY). You are receiving this because you were mentioned.Message ID: ***@***.***>

[SEBinTX]

@cleidigh We are trying to do a similar account backup by using Thunderbird as a way to keep old emails from moving from Gmail to Outlook. But the Outlook is only going to have a 6 month retention period. What do I need to do to set up Thunderbird without an email account and be able to import the Mbox file?

[cleidigh]

@SEBinTX
Good question!
While not it's main purpose, my other addon LocalFolders s the trick.
https://addons.thunderbird.net/en-US/thunderbird/addon/localfolder/?src=ss

Once installed it will allow you to create a Local Folder pseudo account independent of any mail account.
-install

• go to the account settings tab and you will see the LocalFolders button on the main toolbar
• click for add/remove options
• create the local folder where you wish
• you will now be able to see the import mbox options

Note: I would suggest creating a top level folder and import to that.
Thunderbird won't allow you to delete top level folders that have Special names like inbox

@cleidigh

[cleidigh]

Hi Chris,

My initial setup may indeed be the problem then.
When asked to create an email account, I declined that as I only wanted to have a readable archive of my old emails. I have switched to ProtonMail as my main client now.

I requested a takeout package from Google up to a certain date with ProtonMail taking over from then. As I had a Gmail account since 2005 or so, there was a lot to download and the data came in 3 large archive files. Opening the archive zip files just reveals a list of mbox files with any nested folders simply presented as separate files with no info on subfolders or anything like that.

If you don't create an email account in Thunderbird then there is no local folder so after some searching I found your other add-on to create a local folder.

As far as the mbox files import, I have found that importing the whole folder doesn't work. Some mbox files get imported and are readable but others simply create the folder that remains empty. However, that same file will import if I do it as a single file.
Of the 4 options on the import mbox menu, only the "Individual mbox files (with sbd structure) works as expected. The individual mbox files option just creates an empty folder.

I think that my problems are somehow sub-folder related. If I try and import all the mails from the archive file, the single entries seem to be OK but the folders with subfolders do not import. What was baffling me is that they just appear to be regular mbox files that I can view with mutt. I assumed that the nested folder structure was just something implemented in Gmail's client.

One final point is that I can create folders and sub folders with your LocalFolders tool but I can't delete them. I tried a couple of times to use the 'individual mbox files' option, without the sbd option and ended up with empty folders that I can't get rid of. So, in those cases, I imported the mbox files with the sbd option as sub-folders and that worked.

So, I'm getting my archive imported thanks to your extensions and it is actually working out better as I need only import the mbox files that I will reference. The others just remain in the Google archive. I really appreciate the work that you have done to make this possible.

Kind regards
Colin Sare-Soar

Sent with Proton Mail secure email.
…

@Colins2
Great you got things in order.
Thanks for the kudos!
Christopher

[cleidigh]

@Colins2
I am curious about not being able to delete folders. If you have top level folders with special names like Inbox, Thunderbird won't allow you to delete them.
Otherwise I would be interested if there are any errors in the debug console.
Christopher

[Colins2]

@cleidigh Hi Christopher, The folders I created and couldn't delete were not top level with special names. I have a couple of mbox files called 'cookery' and 'crypto' so I created folders with these names and tried to import the respective mbox files into them. What happened was that the import operation created a subfolder with the same name and imported the messages into there. I could delete the subfolder but not the folder on the higher level so maybe Thunderbird was treaating that as a high level folder, albeit not one with a special name? They were created as subfolders of the main LocalFolder, created with your extension. I needed to access a couple of the archives quite urgently to get some information, which I have done, so there is no urgency now. I have wiped the Thunderbird data directory several times and started over. As there is no live account, this is simple to do. I will continue to experiment and see if I can come up with a method that works for all my files. Colin Sent with [Proton Mail](https://proton.me/mail/home) secure email.

…

On Wednesday, December 3rd, 2025 at 07:38, Christopher Leidigh ***@***.***> wrote: cleidigh left a comment [(thunderbird/import-export-tools-ng#825)](#825 (comment)) ***@***.***(https://github.com/Colins2) I am curious about not being able to delete folders. If you have top level folders with special names like Inbox, Thunderbird won't allow you to delete them. Otherwise I would be interested if there are any errors in the debug console. Christopher — Reply to this email directly, [view it on GitHub](#825 (comment)), or [unsubscribe](https://github.com/notifications/unsubscribe-auth/AJQF55IQUPKG74O7L54AB6L37YWJLAVCNFSM6AAAAACNPGPTFGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTMMBUGUZDQNZVHA). You are receiving this because you were mentioned.Message ID: ***@***.***>

[SEBinTX]

Thanks for the input and I think this will work. I have to run the takeout download again as the mbox file was too large. 4GB is the biggest file it will import, so once that finishes I will try again. Regards, Steve Burgess Ready Seal - Rust-Oleum 972-434-2028 - Main 972-200-3060 - Direct 945-994-0118 - Mobile

…

________________________________ From: Christopher Leidigh ***@***.***> Sent: Tuesday, December 2, 2025 6:25 PM To: thunderbird/import-export-tools-ng ***@***.***> Cc: Steve Burgess ***@***.***>; Mention ***@***.***> Subject: Re: [thunderbird/import-export-tools-ng] No import Mbox options (Issue #825) Caution: This email originated from an external source. Do not click links or open attachments unless you recognize the sender and know the content is safe. [https://image-tracking-service.us-1.mimecastcybergraph.com/v1/image?imageData=rKi1ODlNvQEcOn18gG33kNysTlCBHLuxfTuQCyzDIPLwOcD1PD%2FxP4B6mZHHRhSFThGBH6rvyKnNq%2FCE9GIx%2BGvfLWrvZCnDNRJcZ6FcfWCp1rzuNnZq%2FtWT5g3cqqTbX%2F4QzV0A3oJ8QOuf1MLXhvpk8n4MO3XIebwFzT9lVf1KLgIiHy1uA1Db5X7wvCydQiwpideETOs8P9Wjddw7CVmb%2B2kBzWLsuMUOowWIbBiGnK1fJU%2FbfAqFZkcw%2BzPc0z9EliVTqxoQBJ2vOEelKKsDpeVJCNQV6xb5XR9lj321ClJvzc8y%2FIo%3D]cleidigh left a comment (thunderbird/import-export-tools-ng#825)<#825 (comment)> @SEBinTX<https://github.com/SEBinTX> Good question! While not it's main purpose, my other addon LocalFolders s the trick. https://addons.thunderbird.net/en-US/thunderbird/addon/localfolder/?src=ss<https://addons.thunderbird.net/en-US/thunderbird/addon/localfolder/?src=ss> Once installed it will allow you to create a Local Folder pseudo account independent of any mail account. -install * go to the account settings tab and you will see the LocalFolders button on the main toolbar * click for add/remove options * create the local folder where you wish * you will now be able to see the import mbox options Note: I would suggest creating a top level folder and import to that. Thunderbird won't allow you to delete top level folders that have Special names like inbox @cleidigh<https://github.com/cleidigh> — Reply to this email directly, view it on GitHub<#825 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/B3ACBF42PEPQTZA72KGUV4L37YUYVAVCNFSM6AAAAACNPGPTFGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTMMBUGQ4TONBUGI>. You are receiving this because you were mentioned.Message ID: ***@***.***>

[cleidigh]

@SEBinTX
Can you clarify what you mean about a 4GB limit?
ImportExportTools will import 25GB or more.
Are you getting some error message?
@cleidigh