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

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: -06-28_180950.jpg">78673 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.