Unable to delete Mail account using Internet Accounts

[37Shannon]

The past couple of days, my GMail account has not been logging into the GMail server; Mail displays a "~" next to the mailbox and the message "Login failed" appears in the upper right corner of the received-mail window. My PTD email server account is functioning fine and I can receive and send mail using that as normally.

So after monkeying around trying to see what the problem might be, I decided just to delete the GMail account and re-add it. When I attempt to do this in Internet Accounts, though, nothing happens.

Any ideas what's going on here? The Mail app is not running when I try to delete the GMail account in Internet Accounts.

 

[37Shannon]

Update: applying Windows logic to the problem, I rebooted the MAC and Mail is now able to connect to the GMail server. Still puzzled as to what's going on with Internet Accounts.