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Re: rfc2821bis-01 Issue 18: Usability of 1yz replies

2007-04-12 03:27:53
On 2007-04-11 15:07:22 -0400, Hector Santos wrote:
John C Klensin wrote:
But, as several people have pointed out, there is ample reason
to infer an assumption that all codes in a multiline reply will
be the same from the text.

You know thats fine, and its a natural assumption.  But its doesn't 
represent reality and that reality has evolved from the fact it has been 
possible all along to have inconsequential and different reply codes in 
continuation lines.

Remember the ONLY thing that a developer has to go by is a 25 year old 
suggestion and it is the ONLY thing to go by for implementing a 
extremely no brainer concept that the only ultimate reply code is the 
last one, hence why it is in place in wide practice.  It is not by 
coincidence.  Why would any system not USE the only logical suggestion 
for a reply code design is beyond me.

One reason why a system might use the first instead of the last code is
that it just collects the whole reply before looking for a return code.
In this case it is a lot easier to just use the first three bytes of the
reply than scan backwards for the penultimate CRLF sequence and use the
next 3 bytes after that. In just about any programming language except C
and Fortran that approach sounds at least as "logical" to me as using
the last code.

I honestly don't grasp the resistance.

My understanding of the RFC has always been that an SMTP command can have only
one result code and that in multiline replies this (singular!) code must
be repeated on every line. Others seem to have interpreted this the same.
You are the first person I know who interpretes this differently. 

Therefore I think your suggestion is a change in the RFC as it is
commonly understood, and not just a clarification. Such a change would
move the RFC back to "proposed standard".

If this has all to to do with your RFC time-line, thats one thing, but
lets not try to continue to look for reasons to not legitimize what is
really a wide practice.

Is it wide practice? I never encountered it, but I do admit that I don't
habitually scan SMTP connections.


   _  | Peter J. Holzer    | I know I'd be respectful of a pirate 
|_|_) | Sysadmin WSR       | with an emu on his shoulder.
| |   | hjp(_at_)hjp(_dot_)at         |
__/   | |    -- Sam in "Freefall"

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