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Re: /etc/services losses



Greg Troxel wrote in
 <rmicz0447rt.fsf%s1.lexort.com@localhost>:
 |Taylor R Campbell <campbell+netbsd-tech-userlevel%mumble.net@localhost> writes:
 |
 |> `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.

Hm, but especially :25 was traditionally used by MUAs, no?
Who used the submission port ~a decade ago?
(I cannot truly tell about a survey though, here all was TLS,
"always".)

 |> - 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.
 |
 |Yes, they are different, however my take from reading
 |https://datatracker.ietf.org/doc/html/rfc8314 is that the orignal label
 |of 465 as smtps was confused, and that IANA now labels 465 as start
 |
 |> 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.

'Had to read the RFC how that interferes with EHLO reset.

 |It very clearly does not matter.  I think the concern was
 |implementations that treated TLS as optional and would continue.  But
 |that's all rationale for why RFC8314 recommends as it does.  Where we
 |are now is that 465/tcp is submissions and 587 is submission.  And our
 |services file has smtps for 465, but that no longer exists in IANA-land.
 |
 |> I'm not sure if there is any port number that can rightly be called
 |> `smtps' today.
 |
 |Agreed.  I know of no usage that is MUA-to-MUA SMTP over prenegotiated
 |TLS.   It's basically a STARTTLS over 25 world -- which is what I think
 |you are thinkig
 |
 |For this thread, I think all that matters is that we find a reasonable
 |way to update services to match IANA while maintaining local diffs.  We
 |have gotten into a bad state.
 --End of <rmicz0447rt.fsf%s1.lexort.com@localhost>

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)


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