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Re: 2821bis consideration - New 2nd attempt Retry Strategy recommendation

2007-11-15 17:23:21

Hi John,

Ok, I'm not going to waste time with an I-D, so if Tony or others want to address it, great, otherwise, I'm not going to worry about it. :-)

But I want to make sure I wasn't mis-read. To be clear, the suggestion really has nothing to do with anti-spam or even mentioning it. We already have it saving: Sending Strategy


   The sender MUST delay retrying a particular destination after one
   attempt has failed.  In general, the retry interval SHOULD be at
   least 30 minutes; however, more sophisticated and variable strategies
   will be beneficial when the SMTP client can determine the reason for

This was excellent insight done at the time. Maybe that is enough, but I do believe a word smith can finesse a new clause or sentence indicating why a short 2nd attempt may be applicable and highly desirable for improved outbound mail operations. Maybe something like:

   Due to the increase of new SMTP challenge/response receiver
   systems, if the SMTP client sees 451 temporary response code
   for the RCPT or DATA state, it MAY consider using a shorter
   2nd attempt interval, recommended 5-10 minutes.  This SHOULD
   be for the 2nd attempt only.

If not, never mind. :-)


John C Klensin wrote:

Tony may take a different position, but my response to this
suggestion is the same as my response to all sorts of other
anti-spam or spammer-conditioned proposed changes to 2821:
Write a separate proposal, as an I-D, to make the change.  Get
it approved as a Proposed Standard.  Get it implemented and
deployed.  When the timer runs out, get it approved as a Draft
Standard.  Do all of this efficiently enough that, by the time
discussions of 2821ter come up, your proposal will be of full
Standard maturity and deployment so that it can be folded in.

For 2821bis, this would be a significant change to a
long-established piece of protocol.   It is too late, both
procedurally and, IMO, technically.


--On Thursday, 15 November, 2007 17:58 -0500 Hector Santos
<hsantos(_at_)santronics(_dot_)com> wrote:


Is there worth to this?

My recommendation for 2821bis is to include some insights
about or how variable strategies" plays a bigger role these
days and in fact, might be almost an "necessity" for improved
modern operations these days.

Even if one didn't want to incorporate GL into their SMTP
receiver, the default sending retry strategy (if it matches
the current specs) has to be reconsidered due to increased
remote GL systems and the growing probability of hitting such
a system.

In short, they might be need to reconsider the recommended "30
minute" retry interval, at least for the 2nd attempt.

I recommend a 5 min retry on the 2nd attempt, with a fall back
to their normal interval after that.



Hector Santos, CTO