Ok not that this feature is useful for anyone that may really need it but I read about this feature that google just announced called Undo Send.

Now don’t get all excited thinking that google will reach out into the interwebs email servers and grab back or delete your email from other peoples accounts.

The way it is suppose to work is
You send an email and Google delays the send for 5 minutes.
Within that time you can stop the email.

Hmm Not sure who this will be useful for but you never know.

Check it out in your Gmail Settings.