I wish to "detach" a folder from Thunderbird, but keep it available

1. click help>troubleshootinginformation
2. scroll to 'profile folder' and click 'open folder'
3. if this folder is in Local Folders, go to Mail\Local folders. If in POP account, go to Mail\<POP account>
4. once there look for a pair of files with the folder name, such as mystuff, mystuff.msf. Ignore the msf entry
5. COPY the non-msf file to somewhere else, some folder outside of Thunderbird
6. ,now that it is out of thunderbird, you can delete the thunderbird folder
7. to view this file, you can use a PC mbox viewer and a free one is at https://www.majorgeeks.com/files/details/mbox_viewer.html or you can view the messages from the web at this URL https://emailshot.io/tools/mbox-viewer/ although there are others.

mbox files are common, so you may prefer different software or website. the message is that the mbox file can be viewed separately from thunderbird and with these steps you achieve your objective.

Hi David:

THANK YOU, but I do not have a choice of "troubleshootinginformation" under TB 154. Perhaps I should say that I'm on macOS, not Wintel.

That said, I AM able to navigate using Finder to Local Folders. I AM able to see the "non msf" files.

So I should be able to start in your instructions on step 5.

Have I MISSED ANYTHING, please?

Thanks so much, Bob

I would use the add-on "ImportExportTools NG" and export the folders to an MBOX-format files, then delete the original folder. You can at any time later import the MBOXs back into Thunderbird using ImportExportTools NG, or simply copy the MBOX file back into the local folders folder in your Profile (the default location in Windows is "%APPDATA%\Thunderbird\Profiles\[profile name]\Mail\Local Folders".)

starting with step 5 is good. :)

David:

IT WORKED. I was able to export the old company mail, but the real culprit was the decades of outbound mail going back a long time. I was able to get those folders onto a NAS drive for storage, then deleted the folders, emptied the trash and compacted the entire thing.

I think I got where I need to go.

Just to make sure I have a handle on this I have used ImportExportTools to re-import some mail. That's taking a bit of time (huge files), but this proves that I have command (more or less) of this process.

Thanks again, Bob

I'm glad all is well, but give Lin the thanks for the importexport addon. It does simplify the process noticeably. :) JUst a thought: Have you compacted those files? If not, that may reduce their sizes.