The sender and receiver are still necessary for the SMTP protocol to work, as the mail servers need to access that to know where to route the email. At best, t

The sender and receiver are still necessary for the SMTP protocol to work, as the mail servers need to access that to know where to route the email. At best, tor+pgp would allow you to create a pseudonymous email address (or series of addresses), but there would still be nothing stopping people from looking at your mailbox and seeing what other addresses you've communicated with, even if they can't decipher what those communications are. The SMTP protocol itself needs rewritten to function more like tor, so that each intermediary is incapable of seeing the complete picture.