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Re: RFC2821, section and HELO/EHLO

2004-01-02 16:55:45

----- Original Message ----- 
From: "John C Klensin" <john(_at_)jck(_dot_)com>
To: <Valdis(_dot_)Kletnieks(_at_)vt(_dot_)edu>; "B. Johannessen" 
Sent: Friday, January 02, 2004 5:41 PM
Subject: Re: RFC2821, section and HELO/EHLO

Is that what is wanted, or should the ABNF be

       Domain = ( (sub-domain 1*("." sub-domain)) /
          address-literal ) [ string ]

Will this not conflict with other ABNFs requiring an domain specification,
such as MAIL FROM?

      "MAIL FROM:" ("<>" / Reverse-Path)
                       [SP Mail-parameters] CRLF

      Reverse-path = Path
      Forward-path = Path
      Path = "<" [ A-d-l ":" ] Mailbox ">"
      A-d-l = At-domain *( "," A-d-l )
            ; Note that this form, the so-called "source route",
            ; MUST BE accepted, SHOULD NOT be generated, and SHOULD be
            ; ignored.
      At-domain = "@" domain


      mail from: <joe(_at_)example(_dot_)com>
      mail from: <joe(_at_)[X(_dot_)X(_dot_)X(_dot_)X] see contact xyx>

Syntaxtically, it is correct but I question which software expects something
like this to perform the proper parsing. Honestly, this is something we
would have to change in our own server to honor the optional [string] in a
possible domain literal reverse-path.

My input would be:

Since it is only meant to help in the logging/tracking on the helo/ehlo
domain literal and for maximum backward compatibility,  do not have the
[string] element in the domain ABNF, and If possible, to be clear and
specific, add a new  "machine-domain" ABNF:

      helo            = "HELO" SP Domain CRLF
      ehlo            = "EHLO" SP Machine-Domain CRLF

      Machine-Domain = domain [ string ]

This way, there would be no confusion with other ABNF specifications
requiring the domain element.

Hector Santos, Santronics Software, Inc.