I have the same problem re: group MMS to anyone or pic messages to non-iPhone people. None of these options on this thread worked for me. I have never had Onavo and don't even have a Profiles section in my Settings menu. I went into Verizon and the guy reset my network settings and it didn't help either. He looked online (probably at some of these threads) and simply said that it must be an Apple issue that they'll need to work on. The worst part is that I know I'll walk into the Apple store on my appointment time and they'll say that it is a carrier issue. Although people say it's a carrier issue, I see these threads posted for Sprint, Verizon and AT&T.
There is a thread out there that says, for Verizon, to go to Settings>General>Reset and then click Erase All Content and Settings. I'm hesitant to do this right now but may later today, after I write down everything I've downloaded and send my pictures somewhere else to retrieve them later. Someone else said they had success with just using Reset All Settings in the same menu, but I tried this and it did not work.
Hopefully it works because this is ridiculous. First time iPhone buyer and I'm upset about this, even if it's not Apple's fault.