Instructions

1

Open the "Settings" application. Select "General," then "Reset." Tap "Reset Network Settings" and confirm the action. Once the settings are reset, open the "Messages" application to test out MMS functionality. If still not working, move on to Step 2.
2

Navigate to the "Reset" section of the "Settings" application again. Select "Reset All Settings" this time. Again, confirm the action, back out to the "Messages" application and test out the functionality. If this again does not work, you must restore your iPhone.
3

Open iTunes, with the iPhone connected to the computer. Select the iPhone and click "Restore." Confirm the action by clicking "Restore" again. iTunes will erase the iPhone, install iOS again and restart. When the phone restarts, select "Set Up as New Device" within iTunes. If you attempt to restore from a backup file, the broken MMS will most likely persist. After setting up the device as a new phone, disconnect the phone after syncing your media. The MMS functionality should now be fully restored.