smtp.email.us-dcc-phoenix-2.ocs.oraclecloud17.com has no MX records.
Question and response
Question
dig smtp.email.us-dcc-phoenix-2.ocs.oraclecloud17.com. MX
Answer
The response has no answer records.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0