mbm wrote:
No public key encryption system (such as (G)PGP) will help here unless you have the recipient's public key. And public key crypto is not widely used in email.
.. and especially not in Windows houses!
In any case, if my email client were clever enough to pick the recipient based only on a couple of typed characters, I'm sure it could have picked that recipients key to encrypt with, even if it were still the wrong recipient.