Re: Proposal for Adjusted DATA Timeout
At 07:58 -0400 on 05/23/2008, Hector Santos wrote about Proposal for
Adjusted DATA Timeout:
I am wondering if writing a I-D or BCP is worth the effort here and
your comments are welcome.
Basically, with the advent of larger emails and the direction of
mail sophisticated mail receivers performing DATA pre-response
callouts to process the message before determining what the response
code will be, there is a greater potential for client timeout
issues, duplicate resends and messages and of course, wasteful
bandwidths and overheads.
One way to eliminate the duplicates if the SMTP server has accepted
and sent the message but the MUA did not hang around to get the
acceptance ACK (or did not send the QUIT) is to save the Message-ID
of messages that the MUA did this for (I assume the retransmission
will have the same MID. If/when it attempts reinjection, compare the
supplied MID against the saved list and reject the attempt with a 5xx
status code (and text saying "You submitted this already and I
accepted and forwarded it"). You can prune the entry after a
designated wait time or when the message is resubmitted (the latter
possibly before the wait time expiration).