Cannot send email - problem with port 465

[JammyDodger]

I’ve also seen quite a few ‘465 problem’ topics too. My email debugging for anything but the obvious is not great though so I have been quoting the troubleshooting guide:

@Discourse

Email smtp port selection (Using 465?)

The ability to be able to AUTH using ‘telnet’ is extremely important in your first steps of email troubleshooting.

Port 465 (SMTP over SSL) is largely deprecated in favor of STARTTLS on 25. You may need to try alternate ports such as port 2525 or port 587 (Mail Submission) when things do not seem to work as expected.

Is there something we can add to that to help people?