Mms wasn't working for entire week...I spent 5-10 hours a day tryin every combo of Apn settings for mms I could find online... I finally went out bought a new SIM card.. Restored my iPhone 4S...6.1.2...added the Apn settings..
Cellular Data : tfdata
Mms proxy: mms3.tracfone.com:80
Mms max msg size:1048576
Mms us prof: http://www.apple.com/mms/uaprof.rdf
I've tried these settings before.. Didn't work... They do now... Which could believe me to think...may have been the sim... Maybe the phone needed a fresh restore...I would try a fresh restore first before u buy sim. Sim was only 10 bucks... But give it a shot.. Because as fast as I joined net10 a week ago... I was days away from leaving. Hope this helps! Test your mms by sending yourself a picture msg..
Your number email@example.com
this will ensure your not sending yourself an iMessage.. Because iMessages will always work as long as u have Internet/wifi connection.