The bottom line for me is:
Why are e-mails still not safer in these days? Why does no one develope a secure e-mailing system without the need of beeing bound to a company offering keys or such? We are living in the 21th century, e-mail is too out-dated for beeing used that way any longer.
Little bit of money and knowledge and you can set yourself up with an email system so secure, you could lock yourself out of.
Go Exchange!