That is a very bizarre image, the Thunderbird application is not even aligned with the start menu

Perhaps make more readable screen captures the Microsoft way. https://support.microsoft.com/en-us/windows/use-snipping-tool-to-capture-screenshots-00246869-1843-655f-f220-97299b865f6b

What I see is an inbox entirely composed of junk/spam messages. It looks a little like my Gmail spam folder really. Personally I would be using a reading pane to see the content of the messages (F8) but I don't see anything particularly nonsense, except you provider is doing a poor job on spam filtering and your junk filters in Thunderbird must be turned off for that rubbish to not be picked up as spam/junk..

Yes it is bizarre, and that is an exact whole screen microsoft capture . The spam folder and trash folder are fine for that account, and the entire other account is fine too.

Please use the "Snipping Tool" like Matt requested, or some other decent screenshot application. Get a good screenshot of the entire mailbox. It looks like an abandoned email account, because it has more than 28,000 pieces of mail in it. You may need to start manually deleting messages, before it will allow you to read any of them that you want to keep.

I uninstalled and reinstalled TB. Then I scrolled through the nonsense and realized that every single received message including garbage was listed from apparently the beginning of my initial installation. So I started deleting what isn't necessary, and then was told to empty trash and compact and start deleting again. I did this a few more times, and then TB crashed altogether, not even compacting. Uninstalled and reinstalled, same result: not responding. Uninstalled and reinstalled again, and not responding. Unable to compact or anything. Nothing showing, completely blank to even take a screenshot of now. Not even on the other account which didn't have a problem to begin with. Ran Mcafee virus scan and Malwarebytes scan, twice, nothing found.

Snipped image of nonresponding TB.

Image below