I'm trying to find out what port is to be used with "always on" SSL/TLS
(e.g. no STARTTLS command needed, it just does SSL/TLS once the TCP
connection is made, which I understand smtpd_tls_wrappermode=yes will do),
and the RFCs are coming up empty. I thought it was 587. But RFC4409
doesn't say if this is, or is not, SSL/TLS. Some mail clients are using 465
by default, but that isn't even official for anything email related. Anyone
know where this port 465 came from? RFC4409 seems to just be about doing
authentication to allow submission (e.g. submission protocol, smtp with
authentication added). We definitely need to have a port running with
"always on" SSL/TLS so certain access rules can be enforced at firewalls
(that I seriously doubt can be easily made to verify that STARTTLS gets
used). In theory, this would be the same as if I used stunnel listening on
(probably) 587 and reconnecting back to [::1]:25 (aside from losing the
ability to do any connection peer IP address checks).
