Tiger Envelopes lets you read and write mail without worrying about who's snooping on you.
Ordinary email is like sending all your messages on postcards. Anyone who's nosy can read it. What we need is something as easy as envelopes, but for email. That's what Tiger Envelopes is.
You don't need to change your mail client. There are no extra steps. Tiger even puts your message in the envelope for you.
One click to install on Windows, Mac, and Linux. Automatically configures Outlook, Outlook Express, Mac Mail and KMail for you.
It's free and open source, of course.