It can be anything! An apex, subdomain, or even a URL.
Results for*.smtp-private.email.us-phoenix-1.oci.oraclecloud.com
www.*.smtp-private.email.us-phoenix-1.oci.oraclecloud.comsmtp-private.email.us-phoenix-1.oci.oraclecloud.comemail.us-phoenix-1.oci.oraclecloud.comus-phoenix-1.oci.oraclecloud.comoci.oraclecloud.comoraclecloud.comcom