I too am having issues sending pictures. I have a Samsung 8. I was Virgin Mobile and apparently they switched to Boost. Last night this started. I used support text and they tried trouble shooting. Then they said it was a Samsung issue. I called Samsung. Samsung said I needed an APN. I called Boost asked for APN. They said they know it's an issue and try tomorrow. I guess it's a network problem. Good luck!
Having the same issue and I am with boost mobile too!!! I actually bought a brand new one from boost that my buddy gave me a great deal on and its still having the same issue with the brand new one too!!!! Definitely a Samsung issue for sure!!!