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 <[email protected]> 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 <[email protected]>
--
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742 INTERNET: [email protected]
