Smart temporary mail address
NTT Develops "privango" e-mail System
as Junk Mail Countermeasure (press release):
Expiration date, sender's address and/or sender's domain is encoded in a mail address. NTT says these conditions are *encyrpted* in a address, but I'm not certain. It seems that the length of addresses is not enough for such conditions.
This is my temporary mail address that expires on Jan 1th, 2005: