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Re: Improved straw man for retry scenarios

2008-08-10 04:22:58

At 2:56 am -0400 10/8/2008, Hector Santos wrote:
Encourage? Efficiency? Urged? all code for optimization.

I'm all for the optimization, but nowhere in the specifications does it say anything about things behaving differently when you make this optimization.

As I have already pointed out, if you consider the 5XX response to the DATA command or message body to be applicable to a RCPT TO that got a 4XX response, you would get different behavior when this optimization is used.

Another example also just occurred to me, consider a case with PIPELINING of:
  MAIL FROM:<s>
  RCPT TO:<d1>
  RCPT TO:<d2>
  DATA

  250 ok
  450 try later
  450 try later
  554 no valid recipients given

In this case the response to the DATA command definitely shouldn't apply to the RCPT TOs.

Anyway, I guess we will just have to agree we see things a little different but I think we have the same common end goal.

My goal is robust inter-operability. Even if this is considered to be ambiguous, I think the most robust behavior is to consider the response to a DATA command to not be applicable to a delayed RCPT TO. Worst case the delayed RCPT TO is retried unnecessarily, no big deal.

On the other hand, if the delayed RCPT TO isn't retried, and the receiving server is doing some kind of per recipient filtering (eg: what is being proposed in the thread on some sort of limits extension where all but the first RCPT TO would get a 4XX response when the extension isn't supported), mail could be lost.

Glenn.