Enable MMS on iPhone 3.0 without 3.1 Update
After reading all the bad press for iPhone OS 3.1, I decided to hold out on upgrading, which means that I also can’t get MMS working, right? Wrong! The only thing you need to enable MMS on iPhone 3.0 (or 3.01) is the updated carrier file, which you can download from here. After you download the carrier file, type the following command in the terminal:
defaults write com.apple.iTunes carrier-testing -bool TRUE
Do this with iTunes closed. Then launch iTunes again, and select your iPhone, then ‘Restore’ while holding down the option key, navigating to the .ipcc file you just downloaded. The update will take a few seconds, and then all you need to do is reboot your iPhone for MMS to work with 3.0!