iMessage won't send on iOS 7 With my iPhone 5 with iOS 7.0.2 on Wifi or on 3G my iMessages won't send (Progress bar stuck in the middle of the screen).

Rebooting or Airplane mode won't change anything.
There seems to be a bug with iOS7 : 

To make it work again here is a procedure : 


Disable iMessages (Settings > Messages) 
Reset Network settings (Settings > General > Reset > Reset Network settings)
Enable iMessages (Settings > Messages)