ImportExportTools NG has not yet been updated for 78. Help/Troubleshooting, click Open Folder to open the profile, close TB, copy the mbox into the Mail\Local Folders subfolder, restart TB, find the folder under Local Folders in the Folder Pane.

ImportExportTools NG has not yet been updated for 78. Help/Troubleshooting, click Open Folder to open the profile, close TB, copy the mbox into the Mail\Local Folders subfolder, restart TB, find the folder under Local Folders in the Folder Pane.

Okay. But where is Help/Troubleshooting? Is that a button? I dont see it anywhere

(Duplicate post, see above)

Click the 3-bar icon, then Help, then Troubleshooting Information (see picture).

Okay thanks, I found it, but it did not work. I tried restarting and re-doing it a couple time, see screenshot. Nothing shows up

Where did you get your mbox file? If it was exported from Apple mail, the relevant mbox is inside the exported one. Also, the file should have no extension such as .mbox.

From Google account, did the Take out thing straight from my google account and downloaded my emails. That's the file it gave me, this is what it looks like:

Copy the file into Mail\Local Folders, delete the .mbox extension, restart TB.

That did it! What an easy work around now that I know how to do it, now I dont need that addon really. Thanks so much! By the way, if I do that with a 10gb Mbox file, will that cause thunderbird to freeze/crash each time I start it? Or how big of an mbox file can it handle? I assume each time you open thunderbird, it manually loads that file from the computer.

A large mbox file may take a while for TB to index on the first restart, but afterwards there should be no performance issues as long as you follow the general recommendation to exclude the profile folder from antivirus scanning.

http://kb.mozillazine.org/Antivirus_software