*For some reason my phone would not manually let me change the APN settings as the data settings was not present. So I had to work around it.
Alright, I was looking to find a fix for MMS service with T-Mobile. I have an unlocked (Gevey Ultra S) iPhone 4s running firmware 5.1 on baseband 2.0.10. No jailbreak is available, which most of the fixes require. So here is a tutorial on how to get MMS working without a jailbreak.
1) First of all, plug in your iPhone (the phone can be on) to your computer and create a backup using iTunes.
*Right click your device and hit the backup button.
2) Once that is done, you want to download the trial version of iBackupbot.
3) Install the program and run it. Then click on the help tab and click on the register button.
Windows - http://download.cnet.com/iBackupBot-for-Windows/3000-2141_4-10969873.html
Mac - http://download.cnet.com/iBackupBot/3000-2242_4-75532275.html
Input the following to activate the full version:
4) After that is all taken care of Once loaded you will want to find your most recent backup on the left had side and select it.
NAME: AXiS - Fighting For Fun
5) Next you will see a list of files show up in the righthand box. Scroll down until you see Library/Preferences/com.apple.mms_override.plist.
6) Double click on the mms override.plist and it will pop up a box to edit the file.
7) Delete the contents and paste the following script:
8) Save this script and close out the script window.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
9) Now put a checkmark in the box next to Library/Preferences/com.apple.mms_override.plist and then click on the File tab at the top and select restore.