"User is unregistered with iMessage" error message I use an iPod 4th gen and I text my boyfriend on iMessage to his iPhone- either his number or email. Everything was all good until it came up with a red exclamation mark, I deleted the conversations to start fresh but then it said he's unregistered with iMessages. But I can still text my other friends, it's just him that I can't.

We talked it over and he can't text me either. I asked one of my friends to text his number and it worked. I've tried rebooting my iPod Touch, restarting it, making multiple ID accounts-only one worked then later failed. This has been happening for 3 weeks and its hasn't recovered. Anyone help me out? I've also tried iMessaging him on 1 iPad and 2 other iPods, but none of those worked.

How can I iMessage him again?
Go to the "No longer have your iPhone?" section on https://selfsolve.apple.com/deregister-imessage, then turn it on again on you iPhone.