cwl1.oracleemaildelivery.com has no MX records.
Question and response
Question
dig cwl1.oracleemaildelivery.com. MX
Answer
The response has no answer records.
Authority
cwl1.oracleemaildelivery.com. 300 SOA ns1.p68.dns.oraclecloud.net. hostmaster.cwl1.oracleemaildelivery.com. 725156 3600 600 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0