I do not have the option for Group Message and SMS in my Message Settings, and my Iphone 5 won't let me send pictures to people who do not have an Iphone. Is this a T-mobile problem or an Iphone problem?
Try turning MMS Messaging on in Settings > Messages.
If that doesn't do it, see this Apple doc for other ideas -> iOS: Troubleshooting Messages
I don't even see MMS in my Message Settings.
Are you provisioned by T-mobile to use MMS? you should contact Tmobile as messaging is a carrier feature.
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