As of recently I cannot send a SMS to a non iPhone device. Get a message send failure.

Assuming you have text message forwarding set up correctly, the various networks seem to have periods when messages fail to send. If it includes a large picture, I have tried to send small images because I think Apple is sending whatever size you input, and the various carriers have limits on the MMS message size.

I have Sprint as a carrier and am experiencing the same issue. The phone message settings are correct. Not sending pictures just standard messages