I have read on the interwebs about this issue and have not solved my issues 
I have a new Samsung Galaxy s7 edge using default text app
I live in USA and have Verizon
I traveled to Canada and now having issues with MMS. I just got phone last week so not sure if it happens in USA as well.
I keep getting the MMS not downloaded and expires.....
I have my plan on GLOBAL, MMS set to auto retrieve.
Should I try another text app?
Sorry for bringing up an old question again.

I have a new Samsung Galaxy s7 edge using default text app
I live in USA and have Verizon
I traveled to Canada and now having issues with MMS. I just got phone last week so not sure if it happens in USA as well.
I keep getting the MMS not downloaded and expires.....
I have my plan on GLOBAL, MMS set to auto retrieve.
Should I try another text app?
Sorry for bringing up an old question again.