[Top] [All Lists]

Re: Sender's Declaration of Identity

2005-05-17 08:44:22

On Tue May 17 2005 11:07, David MacQuigg wrote:

At 07:19 AM 5/17/2005 -0400, Bruce Lilly wrote:

On Sun May 15 2005 21:23, David MacQuigg wrote:
My main concern is backward compatibility.  Here are the
relevant paragraphs:

    MAIL FROM: bob(_at_)sales(_dot_)my-company(_dot_)com


    The proposed syntax will require extension of SMTP standard [RFC-
    2821] and changes in current MTA software and practices.  See section
    7. IANA Considerations.

    MTA software will need to be enhanced and deployed at sites that
    provide email authentication.  To minimize upgrade efforts these
    changes should be bundled with the upgrade to enable authentication.

    Receivers that don't recognize the ID command should return a Reply

This is NOT backward compatible.  See separate message on ietf-smtp for
an overview and pointers to detailed references.

Bruce, I appreciate your general advice, and I do read it carefully.  I'll 
need something more specific in this case, however.

I assume from the position of your comment above, that you are objecting to 
the expectation that Reply Code 500 could be a normal and harmless 

No, the objection is to sending an extended command that does not have a
corresponding ESMTP keyword extension in the EHLO response.  You need to
establish such a keyword and stipulate that clients MUST NOT send an ID
command unless that keyword is offered in the server's EHLO response. In
that case "Receivers that don;t recognize the ID command" never arises.
That is the established ESMTP negotiation mechanism, and if you don't
play by those rules, your proposal will go nowhere.

All of which is orthogonal to whether or not the extension has any
practical value, as discussed by others.