I know there is a thread on here somewhere about how to fix it, but I can't find it. Can anyone tell me how to fix MMS on a JB iP4 using 4.0.1? I can receive messages but I cannot MMS anyone else.
Im not having this problem, you should try to reset your network settings. If that dosen't work you should restore and re-jailbreak (assuming you have your SHSH saved).
Are you using it JB and unlocked or on official carrier?
Go to Settings > Messages and make sure MMS is switched to ON.
JB and on ATT, but I unlocked using ultrasn0w
Thats why.
Remove ultrasnow and install it only when you need to use the phone with an unofficial sim. Then your AT&T MMS will work fine.
This has been reported by many but not sure if there's a solution yet.
Maybe a future update for ultrasnow will fix it.