no, not the email address is the key, rather a unique string issued by the receiver to each potentuial sender.
In the system I describe, the email address *is* "a unique string issued by the receiver to each potent[u]ial sender." This has the charming property of working very well with the existing e-mail system and without having to have each correspondent manage a directory of "key" words for each person they want to correspond with, updates to that directory, etc.
the email address does not stop spam originating from lets say, hacked windows boxes.
No system does. The point is to be able to tell who leaked/abused/etc it, and more importantly, to be able to trivially terminate the sender's ability to use the address, making that entry on their list completely useless, or better yet, annoying them by clogging up their mail server, if you do sufficiently BOFHish things. ... JG -- Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net "We call it the 'one bite at the apple' rule. Give me one chance [and] then I won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN) With 24 million small businesses in the US alone, that's way too many apples.