How to enable Text Message Forwarding (or SMS Forwarding) on your iPhone
If you get an "iMessage failed to send" message on Porterhouse, or sending to Android phone numbers from your Mac doesn't work, you might need to enable Text Message Forwarding on your iPhone.
Enabling the setting is just a few quick steps, done on your iPhone. Follow the instructions by Apple here: https://support.apple.com/en-us/HT208386 (Note: If you are outside the US the setting might be named "SMS Forwarding" instead of "Text Message Forwarding")
If enabling this setting doesn't seem to work for you, please check out our comprehensive guide on "iMessage failed to send"
How to send text messages from your phone number on your Mac computer
How to send text messages from your phone number on your Mac computer, when you see text messages showing up as being sent from your email address instead of your phone number, or text messages to Android numbers are not being sent at all.
iMessage failed to send
What do do when you see a "iMessage failed to send" message in Porterhouse, or a "Message Send Failure" or "Not Delivered" in your Mac Messages App