I can receive but not send iMessages from Mac in Messages app

[abernardi]

I know this has been covered, but nothing has worked for me. I'm on the last 17" Macbook pro 8,3, late 2011, 2.4GHz i7, 8Gb RAM, running High Sierra OS 10.13.6.

When I try to send a message from "Messages" on the Mac I get the familiar "Not Delivered" with the circled red exclamation mark right away. Here's an example:
View attachment 32369
This is part of a conversation I had with a friend on my iphone, but I made the last entry from my MacBook Pro.

I've looked through dozens of threads on this and other sites and have tried everything I could find including all combinations of signing in and out on the mac and iPhone, restarts, checking forwarding and making sure they have the same preferences.

I did have one interesting thing happen. I logged out of my Apple account in the prefs in the Messages app, then unchecked all the boxes in the "iCloud" and "Internet Accounts" preference panels on the Mac and disabled messages on the iPhone (or maybe logged out all together, can't remember) and then restarted both iPhone and Mac and logged back into my Apple account only in the Messages prefs on the Mac and left the iCloud and Internet Accounts preference panels alone, and it worked for one message. I then logged back into icloud for all the apps that needed it and it stopped working. In fact I got an error when I tried to access the system pref panel for icloud and had to restart which brought it back. Any ideas?

 

[Cory Cooper]

Hello and welcome.

-Which version of iOS on the iPhone?
-Can you upload the image again - it isn't viewable?
-Do you have Enable Messages in iCloud checked in Messages > Preferences... > Accounts?
-Do you have Start new conversations from: set to your iPhone phone number or an email address?

C

 

[abernardi]

Hi Cory, it only took two months to respond, that's pretty good for me!!!

All kidding aside, thank you for responding. I'm on iOS 14.2 now and yes to all your questions. The problem is still persisting. Any ideas?

 

[abernardi]

BTW, just this morning it let me send a garden variety sms message, but not an imessage. It's been intermittent with the sms messages, sometimes yes, sometimes no. iMessages always no.