Undo sending your mail or Take back the send mail

If you make a regret sending a message, you can undo the action by enabling the "Undo send" lab.

 This lab will give you the option to take back a message you just sent.

 this  option will work within one 0r two hours



Follow the following steps :

1. Click the gear icon at the top of your Gmail page and select Mail settings.
2. Click the Labs tab.
3. Find the "Undo Send" lab and select the Enable radio button.
4. Click Save Changes at the bottom of the page.
5. Click on gear icon again and select general tab .
6. Now you see "Undo send " option here and select the time for undoing a message.

This thing is applicable  for Gmail. Please check for other email service provider whether any such option is there or not . if  yes, then  please  let me know the procedure.