Phone still shows up as iMessage after buying android phone
My father had a iPhone 4s, and he decided to purchase the new Samsung galaxy note 2. Every time I try to send him a text on my iPhone 4s, it still tries to send him an iMessage. How can I fix this? When I disable iMessage on my phone, I can send him a text, but as soon as I turn it back on, itvreverts back to sending him a imessage. I also tried to delete his contact from my address book and restarted my phone and it still does it. I also want to inform y'all that I'm using exchange server for my address book. Can someone please help. He also mentioned that he Vthinks others with iPhones have texted him with no issues.
iPhone 4S, iOS 5.1