"EXCHANGE PASSWORD REQUIRED" — AAAAARGH!!!! (Sonoma)

I used to work at a University. I NO LONGER HAVE an email account there, though I still do contract programming for them. I DO, however, sometimes refer to the decades of archived emails, both sent and received, from that account.

I will NEVER want to check mail on that defunct account! BUT, I still want to be able to read the old emails LOCALLY, ON MY MACBOOK PRO, and only there.

I am repeatedly told "Exchange Password Required". I DO NOT WANT TO DELETE the account, thereby (according to a warning) REMOVING ALL LOCAL EMAILS; I want them to REMAIN locally.

Is there any help for this situation? I don't even use Mail.app for current emails; I use Thunderbird instead and my own domain's email accounts. I only open Mail.app when I want to look at these old emails. I get the notification anyway. I cannot turn off the slider next to "Mail" under System Settings -> Internet Accounts; nothing happens when I click on it.

I cannot possibly be the only Mac user in the whole world who needs to keep their archived emails. This is ridiculous.

Many thanks for any solution....

Cheers!

Dave

[ topics, since i can only choose one as a tag: Mail, Sonoma, MacBook Pro ]