Shevek wrote:
On Mon, 9 Aug 2004, Harry Katz wrote:
On Monday, August 09, 2004 10:24 AM ned(_dot_)freed(_at_)mrochek(_dot_)com
wrote:
First, I am not proposing anything here. Not only is
SUBMITTER not my idea, I have been quite clear that I am
ambivalent about its inclusion in MARID.
Second, the optimization in case 1 isn't a failure case but a
success case.
There may be a throughput improvement in some MTAs if the
check can be done sooner. Mind you, I'm not saying there is
guaranteed to be such an improvement
- just that it is a possibility. Actual implementation
experience would be needed to tell for sure.
Ned is exactly correct here. The purpose of SUBMITTER is to allow early
(i.e. at 2821-time) verification of the sender's identity, namely the
PRA. At the IETF meetings last week there was some discussion of
whether this would result in bandwidth saving, throughput improvement,
or no benefit at all. I tend to think there will be modest throughput
improvement, but agree with Ned that we need to verify through testing.
This is incorrect. At 2821 time, we know only who the sender CLAIMS to be
via SUBMITTER. It's not until after 2822 time, when we can compare the
SUBMITTER value to the PRA value computed from the 2822 headers that we
have verified the identity of the sender.
The idea is that the DNS lookup and check can be parallelized with the continuation of the
mail transaction, and then the final response to the DATA payload will be sent when the
PRA matches the SUBMITTER and the SUBMITTER is allowed by its domain's DNS record.
Philip Miller