I am having an issue with SMS relay to my iPhone 5s from my MacBook Pro (2015 model running OS Sierra). Basically it used to work but now it does not. My Mac is not receiving SMS messages sent to my phone, nor can it send an SMS message through my phone to another person. What confuses me is that this was working just fine before and as far as I know none of my settings have changed. Does anyone here have a solution to this problem? When I try to send SMS from my mac it highlights the number in red like the picture below and cannot send it. I know this is a common issue and I have read a number of articles and proposed solutions to this problem, but none have worked in my situation. Most of what I have read says to go into settings-messages-send & receive on the iPhone to activate your email account, however mine is already active and as I mentioned SMS forwarding had worked until just recently. When I go into "text message forwarding" in the same messages menu and deselect my MacBook and turn it back on nothing happens. It does not request or produce a code on my Mac. These are the only two solutions I can find and they aren't working. Is there another issue I am not aware of here? The only possible thing I can think of that may have caused this problem is that I recently updated the carrier settings for my iPhone. Would that have an impact on SMS relay? I appreciate your help.