E - Mail messages are similar to letters, with two main parts. The header contains the name and address of the recipient, (the name and address to whom a copy is sent) and the subject of the message. Some e - mail programs also displays sender's name, address and the date of the message. The body contains the message. Just like the letters, you need the correct address, if you use the wrong address or mistype it , your message will bounce back to you. When you receive an e-mail, the header tells you where it came from, how it was sent and when. Most e - mail programs these days lets you insert a signature at the bottom of the message. Unlike a letter, which is typically sealed in an envelope, e - mail is not used for confidential communication. Messages can be intercepted and read by other people.