Before sending mail for the first time, make sure that you understand how to give a mail address.
1. Enter the command:
mail username@address
You will then be prompted to enter the subject of your mail message.
2. Enter the subject title and press <Return>.
Subject:subject_title
If you make a mistake use the <Delete> key to backup and correct it.
3. Enter the text of your message. Use the <Delete> key to backup and correct any typing mistakes. Press the <Return key whenever you want to start a new line.
4. To send the mail message press <Return> to start a new line and type a full stop. Press the <Return> key again.
Your message will be sent and the shell prompt will be displayed.