Mail.app account/System account

Hi all,
I have an inactive Exchange account showing up in my "Internet Accounts" in the System Prefs panel. 

Its actually really old. It should be deleted and, indeed, it used to be! But somehow, after upgrade to Big Sur, its back from the dead!

When I try to delete it in System Prefs, it goes away for about 15 seconds. Then it reappears, I guess from iCloud keychain!

What gives? How do I permanently destroy this bad guy?

Pavel
Turn off iCloud keychain, and write down or save the passwords/accounts/etc in iCloud keychain. Then remove the account and turn iCloud keychain back on. Restore files, contacts, calendars, and bookmarks from icloud.com and reenter all of the stuff that you had previously written down/saved. Hope this helps.
Mail.app account/System account
 
 
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