> by having such an increduble exploit It allows someone to fake the sender, and have the fake bypass the signature schemes that are supposed to prevent fakery

> by having such an increduble exploit It allows someone to fake the sender, and have the fake bypass the signature schemes that are supposed to prevent fakery. But it's not that incredible; those signature schemes are addons for SMTP, which has always allowed this kind of fakery. That is: I'm not exactly bowled-over to learn that it's possible to fake the sender of an email.