On Fri, Apr 2, 2010 at 1:54 PM, Murray S. Kucherawy <[email protected]> wrote:
>> -----Original Message-----
>> From: Jeff Macdonald [mailto:[email protected]]
>>
>> Ok, so if a system is doing SMTP, it is only concerned with SMTP error
>> codes and NOT enhanced status codes. So if there was a
>> interoperability problem, it would be because the implementation is
>> operating outside of published specs. I think I'm fairly safe in
>> saying this spec (or any other) should not be concerned with such
>> implementations.
>
> I'm unclear on your use of terminology.  If you mean SMTP specifically to 
> exclude ESMTP then you're correct; an SMTP-only client doesn't know anything 
> about enhanced status codes.  But any other client can find out that the 
> server will offer enhanced status codes after EHLO, and then can decide to 
> pay attention to them or not.

ENHANCEDSTATUSCODES is a strange beast. The client doesn't declare it
understands it. The server declares it is using it, even if the client
doesn't understand it. So this is applicable to ESMTP too.

>> > Quietly, the goal of this is useful information exchange between
>> > receivers that try to detect spam and senders that are interested in
>> > some kind of passive feedback from those receivers.  That's probably
>> > MTA-to-MTA.
>>
>> I think this is were it gets muddy. While the receiving MTA may issue
>> enhanced status codes, I think for most 5.7.1 cases the text and code
>> is determined by some policy system. In other words, the MTA has no
>> real knowledge of the policy because that is set by the administrator.
>> It is something that the MTA vendor has already built in by allowing
>> the administrators to set their own policy dynamically. So, there
>> doesn't need to be any MTA code changes to support this draft on the
>> receiving side.
>
> That's correct, it establishes (or should establish) no new requirements, so 
> an MTA rejecting for spam reasons that still chooses to use 5.7.1 isn't 
> suddenly guilty of being non-compliant.

ah, I think I wasn't clear. For [E]SMTP, enhanced SMTP codes don't
really apply to the [E]SMTP session.

>> > But someone using an MUA whose mail is rejected by an MSA using one
>> > of these codes could also be affected.
>>
>> Is there strong agreement that this is a cause for concern? Wouldn't
>> this issue also exist for ARF?
>
> ARF doesn't change SMTP, and so MUAs have no need to know about or understand 
> ARF.

nor does enhanced status codes. Agreed?

>> > I don't think there's any assertion somewhere that a change to the
>> > ESC set is guaranteed to impact MTA behavior; some may be impacted,
>> > some may not.  It's a series of implementation decisions.
>>
>> Ah, yes. But I don't see that as a compelling reason to say this draft
>> presents interop problems for conforming systems.
>
> I don't think anyone claimed it will create interoperability problems.  The 
> point of asking for demonstrations of its interoperability is twofold: (a) 
> prove it works and is useful; and (b) prove that independent implementations 
> based on the spec you've posted can interoperate successfully (i.e. the spec 
> is clear enough).

ah. I perhaps read into previous comments to much.

-- 
Jeff Macdonald
Ayer, MA

Reply via email to