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Re: SMTP Transferred-By-Reference

2007-11-12 09:22:10

John Leslie wrote:
Doug Otis and I have been working up a proposal for a SMTP extension to shift some of the burden of spam abatement away from the receiving SMTP servers towards the originator. It is now published at:

In essence it holds the originator responsible for maintaining the copy of the message until a receiving Mail User Agent determines that it should be delivered to the recipient.

1. <>


They enforce this patents and its follow-ons very aggressively.

2. At best, this reduces total bytes over the but the requirement for a notification message does not reduce the number of network 'transactions' -- in fact it increases them by 100% or more.

3. This presumes that making a real-time decision is a current problem, when it is not generally held to be a major factor among the anti-abuse community. Sure, it would be nice to be able to do it, but it's a long way from the top of the list.

4. It presumes that users can make the right decision. Experience is pretty clear that that's too often not a correct presumption. In addition, having users be required to make this decision burdens them far more than is felt to be useful. (This is a derivation of the transaction cost item, above, except that it moves the decision-making from a receive-side front-end filter to the human user. And of course, it them requires them to wait for the message to show up.

5. Doesn't work so well for disconnected users.


  Dave Crocker
  Brandenburg InternetWorking