I have a factory unlocked iphone 4s and tried putting in the APN settings into my iphone. I was able to put in the following setting:
APN Name: NET10
Proxy: proxy.mvno.tracfone.com Port: 80
BUT do not have the option to put in the following setting resulting in not having the ability to send MMS messages.
MMS Proxy: 18.104.22.168
MMS Port: 80