I have owned an Iphone 4s for not even a year and its worked pretty well in sending messages but for some reason it just suddenly stopped sending messages. its been like this for two days now and the only person it will send messages to is a friend who owns an iphone(all my other contacts own samsungs and other phones) so i figured messages only send to her because she owns an iphone. so I dont really know what to do in this case. PS the messages I try to send just keep trying to send for a long time. they never stop and say failed to send, they just keep going even if im at a place where I have a decent amount of service. sooo im not sure what I can do.