Adam Back wrote:
As started to come out in my response to Tim Showalter there is some
complexity once you start to think seriously about using hashcash:
- mailing lists
need a way to by pass postage requirement for list software
Unfortunately, mailing lists are hard. You want to by-pass the postage
requirement, but only if the sender is a legitmate sender. (And how do
you define that?) How many lists have you been on where a spammer sent
junk to it?
Also, how do you deal with just lists of recipients (as in the Cc line
of this message?) Do you attach coins for each recipient?