I'm using an iPad3 and my wife has an iPad2 and iPhone4. Both iPads are on latest iOS8.1.3 and the iPhone is on iOS 7.1.2. When I use iMessage, I see all my available contacts in blue, and send to them all fine, apart from my wife; I can't send iMessages to her. When I put any of her registered emails into the 'to' field, they end up red, and when I try to delete them I get a message saying "address not registered, do you want to remove it". When she tries to send me an iMessage my contact name is blue but the message sometimes says "not delivered" and sometimes says "delivered" but never appears on my iPad. We can both make FaceTime calls to each other just fine. I have tried resetting network settings on all devices. I have tried signing out of iMessage, FaceTime, and icloud and then turned off the devices, before signing in to everything again but none of these things has helped. All services are turned on and logged into the correct accounts, that's for sure. I hope I've explaind things succinctly, any ideas how we can get iMessage working again?