Are these POP accounts? If so, try COPYing the message folders to Local Storage. Once there, you can safely remove the accounts,

Actually most are imap but some are pop. I was trying to avoid that solution since it used to work but something changed. I was hoping I could flip a switch and get the previous behavior restored.

I am surprised that you can access messages on an IMAP account that is defunct, since that requires that you have access to the online server and that isn't generally allowed for old accounts. I don't think we understand your situation yet. What behavior were you trying to restore?

Imap keeps copies of email locally. I think that's a configuration parameter but it's been 30+ years since I had any in-depth knowledge of the working of Imap. The behavior that I'd like back is to ignore any servers where I unchecked the boxes that would cause T-bird to attempt to download messages. I suspect that they are not attempting to download but are attempting to contact the server for some reason. Before apparently if they didn't need to download anything, they didn't try to communicate with the server. That's my guess anyway 'cause I didn't get those pesky messages every time I checked for new messages. See the image attachment of my original post for the pesky messages. By the way, while your suggestion of just simply moving the messages to Local Folders seems doable, Some of these accounts have multiple sub folders and if T-bird has a way to do a bulk move of folders, I haven't found it. So duplicating all those subfolders and then transferring the messages one subfolder at a time would be quite tedious. Thanks, Jim

Well, you could exit TB, and in windows file explorer, locate the account in profile folder in the imapmail\<accountname> folder and COPY the entries from there to the Mail\local folders folder. restart TB and see all are accessible. Then you could delete those old accounts.