Hi everyone I have a Late 2015 MacBook Pro with the latest OS X High Sierra on it. I am getting a message that says not delivered every time I send a message from my Mac, however when I check my phone it says delivered. This started around the same time I upgraded my iPhone from the 6s to the X. I have checked all my settings to make sure they are only sending from my phone # and not my email. I have tried logging out of both iPhone and MacBook on messages and then logging back in. I am now at a loss on what to do to fix this issue. I know my messages are being delivered cause I carry on conversations thru Messages on my MacBook its just super annoying that they say "Not Delivered"