My husbands S9 has stopped sending receiving mms. I worked with the carrier and we tried everything. I even did a factory reset. They say it is a known issue with S series phones and to contact Samsung. Looking at your message board I see a lot of people with this issue. What is the resolution?
I have newer S series phones that still have working mms.
Samsung Messages use data now, hence they are not SMS anymore.
Check on settings, mobile networks, access point networks.
But it could be your carrier having data issues, you could swap SIM cards or get a trial with a different carrier, to see if it's a carrier problem or your phone.