Hi I agree wholeheartedly with your comments about keeping it simple. I think along those lines that adding hashcash verification to heuristic calculations (as with spamassassin) to help avoid false positives; and creating individual stamps on outgoing messages is enough for a start. To overlay as a next step to do whitelists etc to reduce the stamp overhead can be thought of separately, eg as an optimization between pairs of people who have installed the same extensions on both sides, and so get some extra value and cost saving from that. But the first value should come incrementally, from software installed at one side. So I think the two approaches are complimentary. Ie I think it helps Eric in deploying the more complex whitelist/brownlist/challenge response/captcha etc if others start by deploying the basic hashcash. Adam On Mon, Dec 04, 2006 at 02:48:22PM +0100, Christian Danner wrote: > I followed the recent discussion about methods to use Hashcash for > spam protection. I have to admit that most of those strategies appear > to me much too complex to achieve a better acceptance. IMHO in order > to raise the approval rate deployment and practical operation have to > be less complicated in the first place. Keep it simple! And later on, > if it stands the test, add further gadgets or even build a dedicated > infrastructure.