Maybe you have accidentally turned off your mobile device. If this is the case, all you have to do is to turn on your mobile device.
Maybe the vibrator got stuck. A gentle tap on the back of the device should be enough to unstuck it.
If your device doesn't vibrate at all and its battery is removable try restarting it by removing its battery and reinserting it after 2 minutes.
If you don’t receive the email in the next 2 minutes please check your junk folder, and add [email protected] to your safe sender list.