authentication error with xfinity/comcast started Sept 24 - ports are correct at 465/587 and SSL/TLS forced authentication is selected, but receive “SMTP doesn’t support authentication”
For SMTP make sure you have one of the following combinations, then try again.
Port 587 = Force usage of SSL/TLS
Port 25 = Use SSL/TLS if available
Port 465 = Use SSL/TLS on special port (legacy)
Thank you - The last option worked! I had it on the first option previously and thought I was fine with the new changes comcast made, but it evidently needed the last one.
Same exact problem with Comcast. Trying 465=Use SSL/TLS on special port. So far so good.