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

2007-04-10 12:39:25

Douglas Otis wrote:


On Apr 10, 2007, at 8:41 AM, Tony Finch wrote:

On Tue, 10 Apr 2007, John C Klensin wrote:

    (i) Do nothing, leaving the text as is

I really cannot work out how to make it clearer.

Agreed.

There is no restriction that it can't be used or how it can be used.

First, all it says in so many words is that there no expectation for it because unextended clients do not now how use it. It specifically says:

    Note: unextended SMTP does not have any commands that
    allow this type of reply, and so does not have continue
    or abort commands.

It is clearly vague and incorrect because "unextended" clients do have the abort commands - RSET and/or QUIT. If it is clear that this will break unextended clients, then it should be noted.

Second, there is no restriction in using it as part of a continuation line. Example:

    C: DATA
    S: 352 Begin sending your data
       [client uploads data]
    S: 150-DKIM signature found!
    S: 150-Please wait while we process your DKIM message!
    S: 150-Waiting for trust server to respond...
    S: 150-Still waiting for trust server to respond...
    C: 550-Sorry, The DKIM POLICY has failed this transaction
    C: 550 Please see http://trust-r-us.com/msgid=123213123

Who knows? Is this not possible? It is out of the whelm of real possibility?

Maybe someone will invent a OPES-DKIM shim that needs to call up some trust repository that is taking its sweet time returning with a response or whatever the circumstances, I think 2821bis should be clear either way. Either it is going to stop such possibilities or it will allow for become a helper in future technology.

Please, lets not get into a discussion of where a DKIM or any other DATA processing should be postpone to a POST-ACCEPT design. Thats a not starter for our system and hopefully others in this new era of minimizing accept/bounce potential issues.

--
HLS