Email messages have become very common in large and small companies. Statistics show that the estimate of the number of e-mail had been doubled within every two years. Many people think that email is "informal, confidential and not permanent." Nevertheless, they are wrong, because email can "be obtained, reviewed and maintained by person's unknown sender and sent to the world via the Internet. Letters also are more likely to become permanent, because they can be saved to disk or tape, as the sender, recipient. Many companies already have e-mail privacy policy to clarify expectations of the ...