And I think I did not read your message fully.
I cannot explain the MESSAGE you are getting, but check those things first since the other e-mail clients are working.
What I offered above might not work actually with that message appearing, it could be something else, but look at that first.
Sorry if you already tried that but I could not tell if you had already.
I tried what you suggested but they didn’t work. I tried probably close to 6-7 different suggestions from other websites, still nothing changed. If it wasn’t for Thunderbird I’d be completely enraged. As it is, I’m still mad.