> Date: Thu, 3 Aug 2023 12:41:53 +0200 > From: Hauke Fath <ha...@espresso.rhein-neckar.de> > > IANA appears to have settled on submissions for port 465 (which, > coincidentally, was assigned to 'urd' in the netbsd-5 version, and the > NetBSD addition then declared the smtps alias). A web search for > 'smtps' confirms widespread use, so this should be maintained as an > alias for 'submissions' IMO.
`smtp(s)' and `submission(s)' are subtly different protocols and should not be aliases: - smtp(s) is for MTA<->MTA exchange of fully formed internet mail messages with complete headers. - submission(s) is for an MUA to submit new messages, which may not have complete headers or fully qualified addresses or otherwise be fully formed, via a mail submission agent into the internet mail system. I'm not sure if there is any port number that can rightly be called `smtps' today. I'm also not sure it matters if a TLS session is preceded by the ten bytes `STARTTLS\r\n' on the wire or not.
