SMTP settings for Security and Authentication options - what options with accompanying ports are valid?

[asteroid]

Sometimes I see settings that are not entirely lined up with the settings that I'm normally familiar with such as a request on a website SMTP module to enter values for the "Security" and "Authentication".

• Options for Security: None, SMTPS, STARTTLS
• Options for Authentication: None, Plain, Login, CRAM-MD5, OAuth 2.0

As an example, here's one particular request for such info:


As for the Port number, I usually assume 465, but I also be believe 587 can also be used for STARTTLS from some of what I've read, but I think it's also NON-SSL... So I don't know if that's actually valid.

Could someone please explain what options are valid and with which port(s) they're valid?

Any and all combinations would be really appreciated.

 

[cPRex]

Hey there! This link, once you click the orange button, gives a list of the protocols and ports that are supported at this time:

Set Up Mail Client | cPanel & WHM Documentation

This interface lets you easily configure a mail client to access a cPanel email address.

docs.cpanel.net

Can you read that and see if that's what you're looking for?