Have not been able to get SMTP to work on 1 account. All settings OK. Checked and rechecked. Can’t send mail unless I change port to 25 which is not specified. Should be 465 or 587. Does not like either.
For port 465 make sure the security policy is Use SSL/TLS on special port (legacy)
It is and always has been. Username and password have not changed recently. Maybe I should change password on mail server.
You could try that. Who is your email provider?
The best port is 587, with Force usage of SSL/TLS.
I just had a problem with my smtp link with Comcast: this fixed the problem!