Abstract: Like wearing seatbelts. Like using condoms. Security measures only work if done correctly and done all the time, but we don't use security measures when burden weighs more heavily than risk. That's why e-mail is rarely encrypted. Too difficult. Too costly. Balanced against little perceived risk in sending e-mails in the clear. Our simple, yet secure, e-mail encryption system changes that. It's easy to use—anyone who can use e-mail can use our encryption system. Users pay no charge for basic service—it's free. We make money in other ways. Other e-mail encryption systems cost too much, are too complex, need special hardware, and are not compatible. Ours is safe, easy, and free, and viral adoption can make our system the global standard for sending secure e-mails. With the privacy people get from our invisible, easy-to-use system, e-mail will be safe for everybody.