IPhone receives MMS picture messages, but won't send?

Sorry for the length of this question. I have an unlocked iPhone 4 that was previously on tmobile, but I recently switched over to straight talk. I switched my phone to straight talk using the sim swap method, at first I couldn't get it, but I figured out how to after a while. After I got the data and mms working I sent a picture to two of my friends and they went through. Now, I can't send any picture messages at all unless I'm using iMessage. I can receive them, I just can't send them. I'm pretty sure that it doesn't have anything to do with my transfer to straight talk because I was having this problem when I was with tmobile before I switched over. Does anyone know how I can fix this, it's really annoying. I saw something on a website that said turn data roaming on, I tried that and it still did it. I also saw something about resetting the network settings, I'm cautious about doing that because I'm afraid it will delete my straight talk APN settings and I will have to go through the headache of doing all that over again. I've also tried toggling airplane mode, mms messaging, and iMessage on and off and still I can't send them. Like I said I don't think it had anything to do with my transition to straight talk because I was experiencing it with tmobile as well. If anyone knows how to fix this please help me.

Check the APN settings and make sure they didn't revert back the default settings, I read this sometimes happens when changing them for Straight Talk.

Also go here: http://www.howardforums.com/forumdisplay.php/551-Straight-Talk

Do a search for your problem, you'll find a ton on information for Straight Talk and the iPhone.

  • Why won't my iPhone send picture messages? I have an iPhone 4 and every time I try to send pictures it gets to where the sent bar is almost full, then it just stops and won't send. What do I do? I've tried restarting my phone and it didn't do anything. It is on my plan though. I just sent a picture message yesterday but now it's f*cking up.
  • My iPhone 4 won't send picture messages? I was working ever sense I got it but today it doesn't finish sending and bared exclamation mark appears and says it failed sending. Why is it doing this? It worked before and I already checked my settings and everything is on.
  • My iPhone 4 won't send MMS messages? I just recently got my iPhone 4 last month, so it has the most up to date iOS (5.1.1), however, it doesn't send Multimedia messages (pictures, recordings, and video).It has the camera icon to send them, but when the messages are in the process of being sent, it stops prematurely and says that the file could not be sent. I tried looking for answers to this question elsewhere, but this is the only case I've heard of. Any help is appreciated.
  • My iPhone 4 receives and sends text messages but can't send or receive photos? Barely bought a new iPhone 4, put my sim card into it and the iphone won't let me receive or send picture texts. I can send message texts and receive them, but not picture ones. It keeps giving me an error (red exclamation point) on by my picture. Tried all your suggestions. Still doesn't work and yes I can attach to emails and stuff but just can't text photos.