Sorry, forgot to say, that it's the Windows desktop version I'm using.

can you post a screenshot of the account in windows file explorer? If IMAP, it would be the imap\<accountname> folder or for POP the Mail\<accountname> folder.

Bingo! There it is! Thank you so much, David!  :-) I searched a couple of times for that file without any success.

Anyway, I'd be glad to store all of that stuff on another drive, meanwhile now that folder is located on the system drive and as soon I have to recover the OS-partition I'd have to do a backup of that file first. So I'd be better off with the store-folder on another drive. But how to do that? Just copy the folder's content first to the new location and then change the path in Tb below "Local Folder"? Or shouldn't I copy that folder's content by myself, just change that path and Tb will copy everything to that new location automatically?

How should I proceed?

Thanks again, highly appreciated!  :-)

copy the folder yourself start TB and then change local folder pointer it may force a restart you can then delete from prior location

copy the folder yourself start TB and then change local folder pointer

I copied the last folder's content to a folder named "e-Mail Thunderbird" and entered its location in Tb. After having restarted TB the result was an error message, saying that some certain email-folder couldn't be found. So maybe I should copy the whole path?

Or better use a junction (which originally shouldn't be necessary, if I'm not wrong...)?

Best regards and THANK YOU again. :-)

Your words are vague. You were to copy Local Folders elsewhere, anywhere, not just folder contents. when you restarted thunderbird and located to Local Folders, you were to select the button to browse and locate and confirm the new Location. On restart, thunderbird should find it. I am assuming the Local Folders is being stored on a drive that is always accessible. Do try again or post screenshot of the pane where you select Local Folder.

Alright, David, and thank you again, but I'm confused. Which one of those folders is the "Local Folder" in this path?: C:\Users\[Username]\AppData\Roaming\Thunderbird\Profiles\xyz123.default-release\ImapMail\imap.xyz.com

And besides the last folder named "imap.xyz.com" there resides a file named "imap.xyz.com.msf". Do I have to copy that file as well? Should I then copy the folder "ImapMail" for to already contain both: the folder "imap.xyz.com" and the file "imap.xyz.com.msf"?

Thank you, David. Finally it worked fine just copying the ultimate folder in the path (foldername "imap.xyz.com") and then change the pointer's path in Tb. :-)