sms send issues in text

I'm having issues with sending to non-iPhones using SMS. Often times it is more frequent with trying to send pictures and attachments, which was not the case several months ago with the same phones and same macbook pro summer 2015. It seemed to start when I updated the MacBook but it could have been with one of the iPhone updates. Is anyone else having this issue? It happens on all my devices, not just the iPhones. The Mac, the iPhones, the iPad Pro...

If someone texts me from a non-iPhone, I can respond back to them. However, I cannot initiate a new text to someone without an iPhone. I have every piece of equipment set up properly. Please advise. Thank you.