Re: draft-kucherawy-greylisting-bcp

[Hector <[e-mail]>]

Keith Moore wrote:
> One 'interesting' aspect of an interop test for greylisting is that it would only affect servers.  Greylisting is supposed to be backward compatible with standards-conforming clients.   What you would want to establish via interoperability testing is that a server that implements greylisting per the RFC doesn't degrade interoperability with existing, properly-implemented, clients.
> 
> I don't have a strong opinion of BCP vs. standards-track for this.  I think that if it's desirable to publish an RFC on this topic (which I doubt), either BCP or PS would suffice.   But I do think that if it's going to be published as PS, the document needs to define testing criteria for advancement.
> 

The only factor I see that can come close to degrade testing idea:

   - a compliant MTA does retry per SMTP,  but
   - before the Greylisting blocking time.

A key issue, if you need a reminder is the blind MTA world of varying 
degrees in blocking times and this is why we need a mechanical 
client/server automaton as oppose to a BCP which will end up being 
most likely a subjective "Rough Concensus" of the stronger IETF keys 
and participants making a "Best for all world" compromise offering of 
TIME that will not resolve the central issue:

     BCP TIME < GL Blocking Time => wasted attempts
     BCP TIME > GL Blocking Time => Delayed deliveries.

This has long been measured and of recent measure with internal 
testing of the proposal showing the proof of concept has been a 100% 
success in achieving a minimum of 2 attempts at precisely the delay 
time the server suggested.

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