Since iOS 7 was released I have had a few people coming to me saying that iMessage is not working.
If this is you, then there are 2 methods to try. If the first does not work try the second.
Restart your iOS device by holding down both the power button and the home button until the Apple logo appears in the centre of the screen. release the buttons, let you device fully start and then try iMessage again.
Follow these steps;
- Goto Settings -> Messages
- Turn off iMessage
- Goto Settings -> General -> Reset
- Choose Reset Network Settings
- Go back to Settings -> Messages
- Turn on iMessage
Hopefully after one or both of these options you will be back using iMessage again.
I hope that this help you.