Apple Mail not syncing between macOS and iOS after updates

Well I got it to delete the account. I closed Mail (a couple of times) and restarted the MBA (also a couple of times). Then a couple of hours later, I added the iCloud mail account back in. There were 18 new messages, which I then deleted. Then I checked Mail on my iPhone. The 18 emails that I had deleted on my MBA were still there on my iPhone. Then I logging into my iCloud (using Safari) and opened Mail. The 18 emails that I had deleted on my MBA were also still in iCloud. So, the sync on Mail between Apple devices is not working. I did not bother to check my iPad. I'm going to call Apple Support tomorrow and see what they say.

Thanks for your reply. I think that you will see in the thread that I mentioned that when I tried to delete the account on my iPhone iOS that it wouldn't let me delete it. I even posted a screenshot of the Apple directions of the steps to take to delete it...the one key step..."4. Tap to Sign out or Delete" does not even come up as an option. (Most likely the "How to" team hasn't caught up with the new OS releases.

I delete 50 emails in iOS on my iPhone and then go to Mail on macOS and they are still there. I have my iCloud set to sync.

Thanks. I'll give it a go.

This gets a little scary...the options it gives are not intuitive...what do you think?

Seems like the logical action is "not" to keep a copy but the only option is to "keep a copy" or "cancel"

Just so you can see...the support directions for deleting an email account on iPhone iOS do not match real world.

(I'm going to save a back up of emails on my Mac and try deleting there again)