Automatic forwarding is blocked by default and that mailbox has it set:
"Your message wasn't delivered because the recipient's email provider rejected it"

Chaouki Katrou
0
Reputation points
Hi
I have registred a domain on microsoft but whenever but I have an issue with sending emails to a specific user within our organization's domain, which is registered with Microsoft. Whenever I attempt to send an email to this user using any address from our domain, I receive the following error message: "Your message wasn't delivered because the recipient's email provider rejected it."