I am using Cyanogenmod 12.1 on a Moto E Gen2 CDMA phone.
I could not receive photo messages or group messages (MMS)
Ting support told me that CDMA phones do not need APN.
Problem is whenever I dial a code into my phone, nothing happens, there is no prompt.
From here I added these APN settings:
MMS Proxy= not set
APN roaming protocol=IPv4/IPv6
Conclusion: Even thought I was told CDMA phones do not need APN settings, I think the key here was that I was able to set correctly set the MSSC URL which I used http://mms.plspictures.com
Results: When I send pictures or group messages they take a little time to send but they do in fact send and I can receive them as well. It was better than what was happening before which was just getting a message that there is a message waiting for me that I could never see or download.
Something to keep in mind is that I have only done this test while connected to a wifi network. I am also using the app Signal to send and receive these messages.
Good luck and I hope this works for you.