This is a follow-on to the question "How can I add an email alias to a domain alias in Google Apps?"
A primary domain has been successfully set-up with Google Apps (not G Suite) e.g. domain1.com
A secondary domain alias to the primary domain has also been setup. It has been verified e.g. domain2.com.
Although I successfully receive an email that is sent to bill@domain1.com, the error message "A delivery loop was detected which causes this email to be undeliverable" is received when an email is sent to bill@domain2.com.
It has been 24 hours since the domain alias was added.
Is there any additional step that must be completed?
Best Answer
This has wasted a good couple of hours of my day today.
Log in to your Admin account at admin.google.com
Users / Problem User / User Information / Email Routing
In RED it says End-user routing has been discontinued. You can manage destinations using recipient mapping. You can also create an address list used to prevent routing rules from applying to specific users.
It offers a button to clear End-user routing. I have no idea where this end user routing came from because the account had never been used before today!
Clearing "end-user routing" made the loop go away.