I don't think anyone's suggesting the recipient should pay for e-mail. What we do want is for the sender to pay the recipient's costs, because the recipient's costs are much greater than those due to mere transport.At any rate, no system I can think of outside of e-mail is purely geared towards resolving some sort of receiver pays other than some much-maligned, relatively recent cell-phone systems and even on those there's much activity to either block or change the charging for marketing calls.