I have an iPhone 4 that does not have service, we use it as an iPod really but just moved somewhere that doesn't have any cell coverage, I can iMessage on my iPhone 5 (w/ my AT&T plan activated) no problem as long as I'm connected to wifi. But the iPhone 4 on the other hand just won't connect to iMessage. No error codes, just won't connect. Wondering if its because there is no cell contract on it or if its just being funky. I've restored and updated the software and it still won't work.