Here's the low down: I am on Sprint, currently using an iPhone 4S. My brother moved from Verizon to Sprint and brought his number from Verizon but switched from an iPhone 4 to a Galaxy S3/4(can't remember which) and ever since he made the switch every time I try to text him he won't get it. On my end it'll say the message was sent but he just NEVER receives it. I called Sprint customer service but they were no help, all they told me was to update my PRL which I had already done by dialing ##873283#. My brother has done this on his end as well. I've also tried deleting him from my Contacts list and re-adding him, and that didn't work either. I'm pretty sure the problem is on my end because when he texts me from his phone I'll receive the message, it's just when I text him he gets nothing. I'm starting to think for some reason my iPhone still thinks he has an iPhone because whenever I try to text him it's sent as an iMessage instead of a regular Text Message. iMessage is only iPhone to iPhone, right? But as I said I deleted him as a contact and re-added him making sure to select his phone as "mobile" and not "iPhone" but it still just doesn't work. I'm at my wits end here and I'm hoping you guys can help me because Sprint has been no help and me and my brother have both tried everything. Thanks for taking the time to read this and thanks in advance for any and all help.