my iPhone 5c won't send pictures...at least it didn't until I fixed it! I use straight talk as my carrier, no t-mobile sim card needed
1. turn on wifi
2. open safari
3.type iapnupdatetfdata.straighttalk.com
4. download profile
5. turn off wifi
6. turn off phone
7. open phone and it should work without a t-mobile sim card!
I literally tried everything I knew all the sms and mms options were on I couldnt find a APN option on my phone this finally worked for me I hope it works for you!
I also had to make sure all my profiles were deleted under the general setting to download current one.
my current version of iOs is 7.0.4 and my network bar says TFW hope this is all helpful!
iPhone 5c, iOS 7.0.4, Straighttalk carrier