I am developing a method that I am convinced will work!
I do need you to help me out to make it work though.
So I assume many of you have issues with your iPhones MMS on T-Mobile so here is the real solution (jailbroken or not)
Download iBackupBot (you can also find this online)
You will need to download this file:https://docs.google.com/open?id=0B22m_wKMhBgwYzY5MTQwYTEtNGZlZS00Mzc1LWJmYzItZTI0NTEzYjJkY2Q0
1. Open iBackupBot and search for you most recent backup (backup your phone to your computer now)
2. Search for Library/Prefrences/com.apple.mms_override.plist
3. Open the file
4. Open the file I made you download in the link above
5. Copy the settings from the file I made you download into the file opened from iBackupBot
7. Scroll down till you find SystemConfiguration/preferences.plist and open it
8. On Lines 35, 79, and 209 you will replace what is below apn with:
9. You will see a setting in iBackupBot that lets you restore from backup (looks like and iphone with a green arrow)
10. Your phone will now say restore in process
11. Enjoy MMS
Is it complicated, hell yes!
Does it work, yes!