Hi Susan,
Would you please provide the whole bounce back email (Non-delivery report, NDR) via private message? I can help you analyze the NDR for further troubleshooting. To request the NDR, I have sent a private message to you.
To access the private message:
-Go to the Your details section on the right side of the community site.
-Click Private messages.
-Click the subject title of the response to read the message.
Thanks,
Young Yang