If you are worried that some malicious cracker or your employer could be violating your privacy and reading private emails, Whisper Bot could be of some help. With Whisper Bot, the sender can write a note (in rich text) online and the recipient can retrieve the note via a secure (https) web page.
You may be thinking that if someone can spy on your email, nothing can stop him or her from visiting the URL that is available inside the email. That’s true so in that case you need to have some information which only the recipient knows - like a secret code.
While creating a note, you can optionally set a secret code that the recipient must enter before he can retrieve your message. Obviously, this secret code should not be sent in the email but communicated using another medium like phone or in-person.
Whisper Note may look like any other password protected text notes service but it’s the anonymous and secure part that makes it a bit different.
Also see: How to Send Anonymous Mail