I'd like to know why the Mac no longer supports sending text messages to a non-Apple phone. With my previous Mac, it worked but on the new machine (MacBook Air, Monterey 12.4) it does not. My iPhone (12 Pro, iOS 15.5) does not have a problem doing this. It's incredibly frustrating and very annoying.
MacBook Air (2020 or later)
It's still supported. Regular text (SMS) messages sent from a Mac or iPad must go via an iPhone, because they're sent over the cellular network, so the devices need to be linked. Traditionally this was done with Text Message Forwarding but I believe the newer Messages in iCloud feature makes it possible too. Taking the Text Message Forwarding option as an example, can you check Settings > Messages > Text Message Forwarding to confirm that your iPhone is set to forward messages to your new Mac? Alternatively, do you have Messages in iCloud enabled?
It's still supported. Regular text (SMS) messages sent from a Mac or iPad must go via an iPhone, because they're sent over the cellular network, so the devices need to be linked. Traditionally this was done with Text Message Forwarding but I believe the newer Messages in iCloud feature makes it possible too. Taking the Text Message Forwarding option as an example, can you check Settings > Messages > Text Message Forwarding to confirm that your iPhone is set to forward messages to your new Mac? Alternatively, do you have Messages in iCloud enabled?
Here is a checklist for linking the Mac and the iPhone for messages:
iMessage checklist
iPhone and Mac both logged in to same Apple ID. Try logging off and logging on if necessary.
iPhone Settings => Messages shows iMessage as "on" (sometimes toggling this off and then on fixes some things)
iPhone Settings => Messages shows Send & Receive showing both phone number and email (Apple ID)
iPhone Settings => Messages shows Text Message Forwarding and your Mac is listed and shown as "on" there.
iPhone Settings => Messages shows Send as SMS "on" and MMS Messaging and Group Messaging both "on"
On the Mac: Messages => Preferences shows same and correct Apple ID and "You can be reached for messages at" indicates both phone number and Apple ID (email), and "start new conversations from" indicates the phone number.
* Don't see the Text Message Forwarding setting on your iPhone? Go to Settings > Messages, turn off iMessage, turn it back on, tap Send & Receive, tap Use Your Apple ID for iMessage, then sign in with the same Apple ID used on your other devices.
One last thing: if all the above are correct but the Mac is not receiving/sending texts from non-Apple devices, on the Mac go to Messages and then Preferences then iMessage and select Sign Out, then sign in again.
MacBook Air Doesn't Send Texts to non-iphone devices
