Hello there Film0011

What computer system do you use? Win/mac? What version of thunderbird do you use?

The reason Google gives you a help notification instead of login prompts is that Thunderbird is trying to use an old OAuth2.0 token, which is not working. Furthermore, it does not clean up the old token, causing it to get stuck in the browser cache.

So clearing caches is okay. But Thunderbird has its own internal browser engine, and clearing the Chrome cache does nothing

You have to fix the re hand shake from thunderbird with the UM servers.

Looking at the fix Update the authentication process: Right-click on the university email address in the left sidebar and select Settings. Go to Server Settings, look for Authentication Method, and change it to OAuth2. Now, look at the bottom left for the outgoing server (SMTP). Select the university server, click Edit, and ensure the authentication method is also set to OAuth2

Purge the Stale Credentials Open Settings (found in the menu bar or the hamburger icon). Navigate to Privacy & Security. Scroll down to the Passwords section and click Saved Passwords.... In the search bar, type google, university, Minnesota, or umn.edu. Remove all entries related to those accounts (including OAuth tokens and login credentials). Restart Thunderbird.

The "First Login" Re-Authentication After restarting, Thunderbird may have no credentials. Click Get Messages to trigger a Google login window. Enter your university email, sign in through your university's portal. and click Allow to give Thunderbird permission to access your account.

Note OAuth 2.1 is replacing OAuth 2.0. A full transition is not required immediately, but you should migrate to it to ensure better security, particularly for new projects

Thank you for your reply. I verified that the account was setup for OAuth2 for both IMAP and outgoing servers and I erased everything in the Password area. The problem was still there. I ended up deleting Thunderbird (actually moving it to a flash drive) and downloading a new copy of Thunderbird. Then I found the folder on the old Thunderbird that contained my "Local Folders" and renamed and moved it to the new Thunderbird data folder. This brought back my saved local folder stuff. The "U" server still had all of my recent emails, so I'm good to go at least until the U makes me change my password again next year. One lingering problem: I still get a window popping up from Thunderbird like the old Google help window except it's blank. I think it pops up everytime Thunderbird checks for mail.