Delete the problem message or move it out of the inbox on the server.

Thank you, Airmail.

Did that. Deleted the message (I have it set to delete from the server when I delete messages), closed the program, restarted the PC, and got a fresh repeat of yesterday's message.

I wonder whether it resends that msg every time instead of the new one. I only received the email re: your response on my Droid.

Delete it at the server through the webmail page, not through Thunderbird.

I'm not using a webmail service.

BTW, I'm using V. 52.7.0, and it was trouble-free until yesterday afternoon.

I've also discovered that every time I search for new messages the program says "Downloading message 1 of 24", loads the pesky message from yesterday once again, then stops loading.

It appears to be counting the new legit messages, but not loading them.

Yes it was working trouble free until the problem message arrived. You have a message that Thunderbird does not like on the server blocking the remaining messages. You need to delete it off the server or move it out of the inbox on the server. What kind of email are you using that does not have a webmail portal? You mentioned you can see the messages on your phone. Can you delete or move the message on the server via the phone?

Day 6: Still no change. It still appears that every time the program checks for new messages, it reloads the offending one then decides there are no more.

It will state "Downloading message 1 of 39" then stop.

I fired up an older laptop, and the program works perfectly, including D/Ling new traffic. So it seems like maybe a hiccup in the one installation.

Thoughts? Anyone? Bueller? Bueller?

Thank you.

Well there will be no change while you don't change what you do. Have you tried what airmail suggested here?