Since updating to ios6.1 I have ben unable to send pics to people who do not have iphones. Pics are recieved through imessage after multiple attempts. Pics will upload to Facebook. Have reset with home button etc and Reset Network Settings. Hasn't worked.
to send an image not using iMessage, then i believe you are using MMS right ? because if it's between iPhone, the first alternative will be through iMessage. Maybe you can check your MMS setting. hopefully it's related to your MMS setting.