Originally Posted by ren857
OP, keep in mind that the Nexus 5 is supported on T-Mobile and Sprint out of the box, but not AT&T, so you probably need to change the APN settings for MMS to work. AT&T Tech support should be able to give them to you (if you don't want to google it.)
I'm on T-Mobile and MMS does NOT work on this phone. End of story. Your provider has nothing to do with it. Google has been wkg on a "fix" since Nov 2013 and come up with nothing. People from all over the world on every carrier are having this issue. It's all over Google forums. The above is a logical comment but --> Carrier is not relevant for this issue.