I have a corrupted Sent Items Folder
I have tried the normal fixes - delete the .msf file, use the repair tool... It's just the emails in this one pop account. I'd like to try and export / re-import into a local folder somehow, then copy into the new imap folder. (I changed hosting providers, and now the same email address is an imap, not a pop). I was having trouble with that folder indexing before changing isp's. When I set up the new accounts, and copied the existing emails into the new imap folders (inbox & sent), everything worked fine on every account except the Sent items of 1 account... Any ideas?
Opaite Mbohovái (2)
OK, after reading more, the first solution I wanted to try was mcutbox, but when I went to that Mozilla support page, the link was broken to download.
I later found a Thunderbird extension (that you must add manually) called ImportExportTools. I had a backup of the corrupted mbox file, and after experimentation importing and exporting, I was eventually able to import directly from the mbox file to a folder I'd created under Local Folders. This seemed to work, but I wanted those files to be in my Sent items folder.
This mbox was originally under a pop account. Having to change service providers, the account is now an imap. When I moved the messages into the sent items folder of the imap account, it was ridiculously slow - (like taking 4 minutes to load a few thousand messages).
I eventually gave up on that, and have left the emails in the Local folders. I can live with that. I will consider the case closed. Hope this helps someone.
its.isber.ucsb.edu/guides/exporting-e-mail-thunderbird
here is the utility. It did seem to fix the issues I was having when it imported my messages into the local folder.