Would CentMail be a barrier to emerging email markets in poorer countries?
It is true that CentMail stamps are “free” only when users already intended to make charitable donations, and in fact CentMail may be prohibitively expensive for users in poorer countries. CentMail, however, does not shut out users who leave their messages unstamped (see Question 26), and we imagine CentMail to work in conjunction with myriad other spam fighting tools and techniques. In particular, CentMail eases the transition to alternative economic approaches, such as sender-posted bonds [3], which ultimately may be better suited for poorer users, but which initially lack the appropriate adoption incentives. • Can malicious users undermine CentMail by verifying stamps before the intended recipients do? In the standard CentMail protocol (described in Section 2.1 of our technical paper) malicious users could in theory sniff a network and verify messages not intended for them, giving the impression that a legitimate user was trying to send spam. Although we believe this type of attack
