My son's phone receives MMS and I can send him text messages on wifi calling. Yesterday while at home on Wifi calling I registered for Scout the GPS tool on my 521 and after entering my phone # the program told me to check my messages for a verification PIN number, it never came up at least not until I went for a walk 3 hours later while I was on cellular.
Five times I had tried and I got 5 PIN numbers. Anyway that's not too much an issue for me, as long as I can text my son from my house it's fine.
Regarding Wifi Calling reliability on the 521, I have it better than some, at least it will connect if I persist with all the voodoo tricks and reboot. It's weird, sometimes I'll be walking up my driveway and wifi will kick right in and turn the icon green,some other times it's like watching milk boil it just takes it's time.
I like the phone, it's my first Smart phone, I thought the 521 would be a good phone to learn with, and at $30 a month, you can't complain. 100 minutes with unlimited Data up to 5Gig of 4G then over on 2G with unlimited messages for 30 bucks is a great deal.Being able to get online just about anywhere is a big plus for me. I'm not much of a yaker so 100 minutes will do fine for now.