Resets didn't work. I had to manually add the settings for the MMS APN. After that it worked right away.
So my issue with mms is a bit...odd. I have a 1520.3 on T-Mobile. I can't send a message to someone with an image (mms), but I can send a text. If that person replies, or sends me a message, I can then send an image and MMS works. I just can't initiate a conversation with an MMS.
Anyone have any ideas?