Ive been working on this problem for a week. At&tT S4 rooted on 2 different ROM's back to stock through ODEN and the MF3 OA update and ABSOLUTELY no mms on Go SMS Pro. Heres where I am at the end of the day. I can use stock messaging app to send and receive mms. If Iphone users want to have a group messaging chat then I have to go to Go SMS Pro, stock Samsung messaging app DOES NOT WORK for Iphone group messaging. Now how stupid is this of Samsung! No wonder people use Iphones, 1/2 of the people using them hate them but at the end of the day each stock app like email, sms, mms, all WORK with every device on earth! Samsung could kill the world market if they would produce ONE phone that works with any phone, operating system. SO go buy ya an iphone, less brain damage.