This happens with my wife's HTC ONE (last year's model). She pointed it out to me last night. Some MMS's go through, some do not. Says something to the extent of it being too large. I've tried different Txting apps (go sms, handcent) with the same problem.
I'm starting to think it may have something to do with how T-Mobile has her line set up. I plan on calling them during the day tomorrow.
Posted via Android Central App