On Aug 17, 2009, at 8:38 PM, John Levine wrote:
The model is like a simple C/R involving Message ID of a mail. The sending domain provides the Message ID and allows computational time for the receiving domain and then query the sending domain to send the message.This model has been proposed many, many, times before. I suppose we should make a page for it in the ASRG wiki of anti-spam techniques even though it'smore of a mail system redesign than an anti-spam measure.
If you do, mention RFC 2017. Cheers, Steve