Unable to send mail from iMac
I get the error :
The server response was: Authentication required prior to MAIL/SAML/SEND/SOML
When I click on "edit SMTP server list", the list is empty.
I can receive mail from the iCloud IMAP server. Also I am able to send mail via iCloud with my iPhone and via iCloud.com using safari on my Mac. I have tried signing out of and into my iCloud account. Apple support says they are aware of the problem. 🤔
Thanks Graham. I just wondered why my wife's computer on using the same SMTP server from the same router has no problem. I also have developed the persistent reminder problem described here over the same time period. I suspect iCloud weirdness, but can't begin to understand the problem.
I certainly agree that when Apple says they are aware, it may boil down to waiting.
From the error message you're seeing I believe the problem is somehow related to the mail server not recognising, or not receiving, the "authentication token" that is stored in your Mac's keychain. Given that you have signed out & back in to iCloud I would assume your Mac has therefore been given a new valid token and, again, that it is a problem at the server end. (But could be a strange glitch in macOS.)
The algorithm for which actual server in the Apple ecosystem deals with which account is unknown but it is quite possible the accounts of you & your wife are being routed to different authentication servers.
PS. Moving this thread into the "Mac Questions" forum.
"When I click on "edit SMTP server list", the list is empty. "
I've resolved this by removing and re-adding the account. Have you tried that yet?
I have. A message reports "this account already exists."
I was able to send email today. Not sure this will last. It certainly seems like a low-profile fix by Apple. I notice throughout my problem the status of email on the iCloud site was green. Glad it wasn't my electric service.