> If the person doing the verifying is a human, they don't need the stamp That was my thought too. Can it be improved? If there is an API to create a unique ke

> If the person doing the verifying is a human, they don't need the stamp That was my thought too. Can it be improved? If there is an API to create a unique key based on the contents of the message (and the headers) that the client can then verify with centmail (or w/e). Sure it wont do anything for mail NOT covered with centmail. BUT you can dump anything with a faked key (likely spam) and let in those with a real key. Then anything else goes to the spam filter as usual. Kinda like a more worldly version of PGP signing. Obviously that kind of scheme would require much more support from email vendors.