If you have a jailbroken iPhone that is running the 3.0 and want to add MMS capability to it read on!
Start by connecting your iPhone to your PC and closing iTunes
Next, download this file: ATT_US-5.5 and save it to your desktop
Nowwe need to get to a command prompt.
Now you have a Command Prompt window open like this:
Type the following string EXACTLY as show and hit Enter:
“C:\Program Files\iTunes\iTunes.exe” /setPrefInt carrier-testing 1
If you get an error, you didn’t type it in exactly as shown above. If You hit Enter and iTunes opens – you didn’t type it in exactly as shown above.
Open iTunes manually
Select the iPhone you want to add MMS capabilty to. You can use the same computer to update several phones. I did both mine and my wife’s on my laptop.
Now press the SHIFT key and click UPDATE (Notice that I have not updated my phone to version 3.1)
In the bottom right-hand corner of the dialogue box is a drop-down box. Change it from “Ipod/IPhone Software (*.ipsw)” to “iPhone Carrier Configuration Files (*.ipcc)”
If you don’t have the ability to select “iPhone Carrier Configuration Files (*.ipcc)” then you missed something above. Most likely you didn’t enter the command correctly.
Select the file you download earlier (ATT_US-5.5) and you will see the progress bar zip by as the change is applied.
Reboot your iPhone:
Once the phone has rebooted go to your messaging and select a contact to send a message to.
You will see the camera icon is now available:
Tap the camera icon, take a picture or choose an existing one . . .
YOU Sir or Ma’am, are ready to send MMS messages on OS 3.0!