Some remailers (read: Mixmaster) include a destination.block capability. The target can be taught about mail filters. The target can ask the remailer op to remove the particular alias, after verifying that he receives mail sent to it. Too clever by half solutions such as ZKP would work, as would the remailer-op sending an arbitrary message encrypted to the complainer to the address in question. If the complainer gets the message, either he's sniffing well, mucking with the DNS, or is the intended recipient of the nym server. Adam Alan Bostick wrote: | Thousands of horny net geeks will send in the message; some of them | will even follow instructions correctly so the remailer forwards the | message to its intended target. The result is that the target will | be mailbombed -- and the remailer operator can't stop the abuse by | blocking the abuser's address, because it's coming from all over the | net. | Cypherpunks: is there any way to respond to, or prevent, this sort of | attack short of actually shutting down the remailer? -- "It is seldom that liberty of any kind is lost all at once." -Hume