Is this a profile or just an mbox? The import feature you are using is for a profile. If it is only an mbox, my suggestion is to:

1. unzip to a local folder
2. install the addon, imporexporttools NG,
3. highlight Local Folders
4. rightclick and select the importexport option to import mbox and then locate and select the unzipped file.

I installed the extension in the attached screenshot. Is that what you suggest?bold text

Also, it appears I only have the option to import or export a Profile, unless I am missing something. Thanks for the help David

Please follow my instructions: - highlight Local Folders, - rightclick and select importexport option to import mbox

I am sorry I am so clueless. "Local Folders" where in Thunderbird of on the computer?

This crazy. I select the file to import and it starts importing an existing email backup from years ago unrelated to the file I selected. I have never interacted with such a frustrating extension.

OK, can I import a .PST into Thunderbird with NG import/export?

No. That isn't a mbox format. If you do a websearch for importing pst to thunderbird or to convert to mbox format, I think you will find a number of sites.

Let's clarify what you are trying to import.

You asked about "a zip file of an MBOX file for entire email account". That does not make sense. mbox files are not usually zipped, and they do not hold data for an entire e-mail account. Profiles get zipped and they do hold data for an entire e-mail account. Combined with this statement ...

This crazy. I select the file to import and it starts importing an existing email backup from years ago unrelated to the file I selected. I have never interacted with such a frustrating extension.

..., the evidence suggests that you have a backed-up profile that you are treating as an mbox file.

Then you asked about importing a pst file, which is a third thing that you could import, but that would require a third, different approach.

What exactly are you trying to accomplish?

I agree, we need to know from exactly where this mbox came from, what application created it, and what OS.

Hi All, I'm having a similar issue to Rick,

Here are my details: We used Google Vault to export a select number of emails as .mbox files. They were zipped after the download from Google Vault, and I have since extracted the contents. I can see the contents of the emails in Notepad++, but when I try to upload them to Thunderbird via the Account Settings, the newly created folder is empty (this is after a restart).

I should note that this feature has worked before for other Google Vault downloads.

I've tried using the ImportExportTools NG extension to see if I get different results, but each time the folders are empty.

Anything else I should try? OS: Win10 22H2 19045.6332

If this should be a different thread, just tell me to jog on.

We used Google Vault to export a select number of emails as .mbox files. They were zipped after the download from Google Vault, and I have since extracted the contents. I can see the contents of the emails in Notepad++, but when I try to upload them to Thunderbird via the Account Settings, the newly created folder is empty (this is after a restart). If this should be a different thread, just tell me to jog on.

Yes, would you please start a new discussion?

But I cannot resist this much for now: if you have extracted the contents of the zip file and you have mbox files, all you have to do is copy them to the "local folders" folder of your profile, make sure that they do not have extensions, and re-start Thunderbird.

I don't know anything in general settings or account settings that would help import messages.