Hi. You and I have talked on the phone before re: jobs at Yahoo!. But, The one part which I don't like is that there is no alternative to the "From:" field for specifying the originating domain. I would favor an extra field where an alternate "From:" could be specified, but another field specifies the domain of the MTA that it was sent from. This way, people using e-mail forwarding aliases (via forging the From: line) will also be able to sign their sent messages. My main fear is that, at some point, some companies/persons will stop accepting mail that has not been signed due to the possible CPU overhead involved in accepting such unsigned mail. The above addition would at least allow an alternate way where sophisticated users & ISPs will still be able to get their mail delivered even if such a "mass blocking strategy" comes to pass. Thank you for considering my ideas.