I tried to set up iMessage with a couple of cousins of mine who have iPod touch. One of them has an yahoo account and the other a hotmail account and I have a gmail account. When I tried texting them, with the yahoo account it work fine but with the hotmail it didn't. I added another email to my profile, and it apparently worked fine, with both, for a while, but then, as they sent me messages, I couldn't respond, I keep typing but the Send button is disabled. I received their messages but I can't sent them anything back. Anyone knows what could be wrong?