Apple Mail says "account already exists"

HI, Eric: Thanks for your reply. I suspect that part of my problem was iCloud. I don't use it, never have, but for some apps to work, I had to have it on. For this purpose, however, since my account ID is the same as my email ID, I noted several forum users indicated this was a problem. So I went through my iPhones (x2), turned iCloud access off, and didn't realize until later that the iPad we have (for my wife's game) also had it enabled. I shut it off, and this AM, when the Mac came back on, viola, emails were loaded and my Mail account was listed (Apple magic...). But now I'm back to the original problem I had, which is that Mail doesn't keep my server settings. Sheesh, Apple has really dropped the ball on their OS and desktop apps.

Opening the app with the shift key down is a trick I've forgotten about, so thanks for reminding me. I'm sure your reply to my problem would have worked as well, as I recognize that you are a treasure to this forum. I'll try hard to remember it in the future.

jw

As you can see, I'm attached to my computer, struggling to figure out the inconsistencies in Mail performance. In answer to your question, yes, I have to manually reset my server settings just as you suggest. My domain is verizon, which is now run by AOL. AOL has me change the outgoing port to 465, whereas the automatically selected port is 527. However, whenever I try to save the configuration, it returns the error "account not verified." I'll exit without saving (my only option), then for some reason, at some point in time, it magically downloads my new emails and sends my test emails, obviously logging me in and accepting my configuration; as it just did. I have no idea why...BTW, just in case Little Snitch is an issue, I've turned off the network filter and selected "allow connection attempts."