Group messaging is MMS. Is his MMS configured properly and working?
I would think so. When he sends a group message we all get it. But if you reply to the message he will not get it but the other person on the group text does. We all had iphones until he switched. I assumed imessage was still used even in group potentially unless one of the group doesnt have a i device.
I just looked at another group conversation I have on my phone and it says imessage at the top. Everyone on that conversation has an i device.
I also just looked at the conversation with the guy that switched to the S5 and another buddy who has an iphone. I had totally deleted the guys contact who switched phones and deleted the conversation string I had with him in it. He sent a picture recently, then a short message. The label over his part is text message. Then the other guy on the conversation commented on the photo and it says imessage. The guy with the s5 did not get that response.