Re Connection Doctor. Does it actually fix things or merely diagnose?
It shows the progress through the steps of fetching or sending mail. It's fairly verbose, and usually displays somewhat useful error messages. MUCH better than just getting a "DING!" and a zigzag to the right of your inbox.
it used to be incredibly
confusing to read if you had more than one account set up, as the debug messages were being added to the log in the order received, not grouped by which thing was being checked, so you'd get the lines intermixed between all your accounts. EVEN THE ONES YOU HAD DISABLED, making it difficult to get anything useful out of it. I think apple finally fixed that. But it's not usually a problem if you only have one email account set up.
I did not do the PW drill as I presumed that was not related. Ah, learning is such sweet sorrow...
Learned that from experience. I've seen several cases where mail was, for reasons unknown, not able to access a password in keychain. Also found cases where TWO entries were in keychain for a single thing (I don't mean one for send and one for receive... I mean TWO for receive) And mail was accessing the first one which was wrong. So it would prompt to re-enter it. And would update the second
one... BRILLIANT! Solution? delete both.
Re Web Access. Not sure I understand. How do I check that? (all other devices, my iMac, iPhone, and iPad had web access). Is that what you mean?
You'd need to contact your ISP and see if they offer access to your email via a web browser. It's a very basic and good "first thing to try" when troubleshooting email issues. Makes sure your password is correct and accepted. I've seen cases where mail was being given useless error messages by the mail server, or just outright hanging up on mail. But when you went to the web interface it says something like "oh you're locked out due to too many failed attempts!" or "we noticed you were trying to read your email from a mobile device and so we blocked it, would you like us to stop blocking that?" If nothing else, it'll let you use your mail until you get your computer fixed. (or give you time to troubleshoot it)