Can send text on iMessage to one person but not pictures? I've been having problems with one of my contacts (zero problems with anyone else) 
I can send text iMessages and they go no problem, but all picture messages fail. 
I can FaceTime her fine, I can send pictures to everyone else. It's just baffling me. Any ideas?
I had this issue too. The person who is trying to receive the image needs to reset their phone. To reset just hold the home button and the lock button until you see the apple sign. This solve my issues and now we send images again both ways