In any case, ATPS, TPA, and its variants all run up against a whitelisting
scaling problem. I think that's the more interesting thing to discuss.
I completely agree. Dunno if that belongs in ietf-822 or ietf-smtp.
It seems to me that the way you scale is to limit the number of
whitelists, and leverage the information that large players already have,
e.g., the 30,000 mail hosts that Yahoo said they knew they broke.
Regards,
John Levine, johnl(_at_)taugh(_dot_)com, Taughannock Networks, Trumansburg NY
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