Did you know that Gmail allows you to retrieve an email sent by mistake?
But before, you must enable this feature in Gmail Labs. And then each time you send an email using the submit button, you will have about 5 seconds to recover an email, in order to modify or even delete it. To do this:
To open Gmail via Google labs, follow this procedure
Find the "Undo Send." Check the "Enable" and click "Save Changes "
Thereafter, immediately after sending a mail with "Send" button, you'll see the link "Undo" to the right of "Your message has been sent." Click "Undo" if you want to retrieve the mail.
Remember that you only have about 5 seconds to retrieve mail sent.