As question says above. It used to update every few minutes, but recently I've had to manually refresh each of the applications to get it to run
Try this: Go to settings ==> apps Find yor mail app Force it to stop Deactivate Reactivate Find your the mail amongst all your other apps and setup your mail account once more. Your gmail settings do not need to be set up again. Add the app to your homescreen again.
I do not know why it stopped working or if there is an easier solution, but this worked for me....:-)