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Re: deja vu: draft-grandhi-pc-smtp-00.txt

2005-05-04 12:45:11

On Wed, May 04, 2005 at 10:00:34PM +0530, Arun Sankar wrote:
to apply to it. But it is the same case with a broken MTA who may have 
the Cc not implemented properly.

Ok, I'll give you a mantra:
   rfc2821 is different from rfc2822.
   SMTP servers don't care about mail headers (**)

If you type in addresses to the 2822.To and 2822.Cc and 2822.Bcc and
2822.From lines in your mail client it is in the scope of the MUA to
"translate" them to correct RFC2821 syntax, i.e. send appropriate
MAIL FROM: and RCPT TO: commands in the SMTP dialogue and remove any
Bcc: lines. A SMTP MTA doesn't even know what those funny characters
are/mean, which it receives during the DATA (Dont Anytime Touch Anything)

If in real life you write a letter (this is rfc2822) and give it to your
secretary (i.e. your mail client aka MUA) to make copies and send it to
the recipients and add them to your real life post folder s/he has to
put it in envelope(s) and put addresses on them (this is rfc2821).
And it is also in the scope of your secretary (aka the MUA) to write
correctly addressed envelopes taken from the information in your letter
and maybe the post-it [tm] on it saying whom to send a carbon copy (Bcc)
to and to not make copies with the post-it on the letter.
The postal system (this is the MTA) doesn't look at your letter inside
the envelope to see where to send it to. They don't care what is inside
the envelope and it is neither their job nor does anybody want them to
do that and read their letters.

So no MTA cares about the headers you add to your letter or the
information you put into the envelope.

Talking about the SMTP MTA (aka RFC2821) being responsible for recognizing
the contents of the mail headers (aka RFC2822) liek To:, From:, Bcc:,
Cc:, ... is simply bullshit (**).

So, let's repeat our mantra from the beginning:
   rfc2821 is different from rfc2822.
   SMTP servers don't care about mail headers (**)

Ommmm ...


** There is one (valid?) exception I know of:
   some MTAs looks at the number of Received: lines for the sake of loop

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