Re: We need an IETF BCP for GREY LISTING

My long 30 years of mail engineering experience has given me the 
position and view that non-timely delivery (i.e. unreasonable 
hindrance) is the exception and not the rule. I don't believe the 
industry would of endured such a poor history of operations and I 
believe, possibly unlike some others, all mail systems were designed 
to deliver mail in a timely matter. I would certainly get out of the 
market if this system became a "game" with laissez-faire attitudes 
that SMTP is a matter of just flipping a coin, heads and tails.  No, I 
still believe there is a strong ethical engineering responsibility by 
the majority of the SMTP systems, in total that make it all work, who 
still believe timely delivery is important. If that was not the case, 
for me, I would of been long out of the market.
That said, I do worry that Greylisting (GL) is growing with a varying 
non-consistency - overhead are increasings. There is no IETF guideline 
and IMTO, its about time it did.  I recall, not too long ago, many key 
people here thought GL was wrong (hence the idea of a IETF I-D was not 
even a consideration) and today, you see these same people are GL 
implementators.  So attitudes have changed to accept GL with an 
effective slightly lower the "SMTP Quality" in the name of SPAM.
Its the same thing with CBV (Callback Verification). CBV works 
wonderfully, but its not something I would recommend to be used 
widely. It would not scale.  Its not something everyone can do.
I am suggesting that we begin to nip this GL bud before it gets out of 
hand, when every server you hit has implemented GL and if left as is, 
in essence, every transaction will now take two or more attempts.
Just imagine if GMAIL.COM began to do Greylisting?  One can stand 
maybe YAHOO with its GL derivative, but with more of the bigger ESPs 
doing the same thing, and it will get out of hand.
I will say that if left as is, the SMTP recommendation of an initial 
short delay, is not effective any more - you might as well leave it to 
1 hr per each attempt and you might be better off for non-wasteful 
deliveries.
--

Richard Kulawiec wrote:
> On Sun, Oct 16, 2011 at 01:42:18PM -0400, Hector wrote:
> > Here is the thing, IMO, the prize at the end of the day is:
> >
> >       Fastest, less waste in Delivery and High Throughput
> >
> > For many, an email today has "No Value" tomorrow, especially in the
> > business world.  I'm sure that is the normal expectation for most
> > systems and people expecting timely emails.
> The problem here, I think, isn't the technology: it's unrealistic and/or
> misplaced expectations.  If I might quote my own haiku on this subject:
>
>         Mail is not the web
>         Mail is not for file transfer
>         Mail is not I M
>
> It's certainly true that a subset of people expect mail to be very
> fast; it might even be true that this subset is large enough that
> it's "normal".  But I don't think that necessarily means we should
> engineer to meet that expectation, just as I don't think the propensity
> of some people to attempt transfer of 100M files via email means that
> we should engineer to make that feasible.
>
> On the other side of that, I do recognize that inordinate mail delays
> do occasionally matter; but I'll argue that (a) these are rare, absent
> outages/misconfigurations that would still persist even if greylisting
> were handled very effectively and (b) these are often caused by
> non-greylisting measures of dubious use.  (I'll cite "quarantines" and
> "quotas" as examples of the latter, but will omit for brevity the lengthy
> arguments I've made elsewhere about why they're a horrible idea.)
> (And let me cite "poor choice of mail service technology or provider"
> as another, especially in light of the past week's events involving
> a well-known operation which is experiencing systemic, prolonged outages,
> please see the NANOG list for extensive discussion.)
>
> Maybe a shorter way to put that last paragraph is that if we agree that
> reasonably timely delivery of mail is a Good Thing, then I think we have
> many other problems to tackle before we turn our attention to greylisting.
>
> ---rsk
--
Sincerely

Hector Santos
http://www.santronics.com