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Re: Language editing

2013-05-06 21:19:03

        You missed the point RFC 5321 SMTP clients have to operate
        with RFC 2821 SMTP servers when sending address literal in
        the HELO/EHLO.  Code doesn't magically get updated when the
        spec is updated.  It takes years for changes to trickle
        through.  The code has to be written, then it has to be
        deployed.

        [The who SPF issue is about a WG that is too impatient to
         wait for the updated code, that has been written, to be
         deployed.  That will happen as OS's get update / replaced.]

        While RFC 4291 relaxed the address syntax, RFC 5321 didn't
        because to do so would break interoperability.

        RFC 5321's address literals are a subset of RFC 4291's
        permittable address formats.  So there is nothing wrong
        with referencing RFC 4291.

        Mark

In message <20130507012924.GX23227@verdi>, John Leslie writes:
Mark Andrews <marka(_at_)isc(_dot_)org> wrote:

Apples mail client is broken [IPv6:2001:df9::4015:1430:8367:2073:5d0]
is not legal according to both RFC 5321 and RFC 2821 which is all
that applies here.

   I was until today unaware how strong the feelings are on this
"one-or-more" vs. "two-or-more" issue. I do not expect to change
anybody's mind. :^(

   But I do object to calling that EHLO string "not legal".

   The 5321 reference names RFC 4291 as the source of address syntax
(even if it gives BNF which says "two or more" if you delve deeply
enough).

   RFC 4921 is clear about saying "one or more". The Errata posted
against it claiming it should say "two or more" have been rejected.
It is silly to argue under these conditions that Apple's EHLO string
is "not legal".

   BTW, RFC 5321 still contains the language about
" if the verification fails, the server MUST NOT refuse to accept a
" message on that basis.

so IMHO enforcing any particular interpretation of what an IPv6
address literal should look like is double-plus-ungood.

====

   To the casual observer, it looks as if RFC 4291 relaxed a previous
"two or more" requirement, but there are folks who don't want to
accept that relaxing.

   One can accept the idea that this relaxing has failed, yet still
observe "liberal in what you accept" as trumping it. I truly wish the
folks in the "two or more" camp would do so!

--
John Leslie <john(_at_)jlc(_dot_)net>
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka(_at_)isc(_dot_)org

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