vap1.oracleemaildelivery.com has no MX records.
Question and response
Question
dig vap1.oracleemaildelivery.com. MX
Answer
The response has no answer records.
Authority
vap1.oracleemaildelivery.com. 300 SOA ns1.p68.dns.oraclecloud.net. hostmaster.vap1.oracleemaildelivery.com. 437230 3600 600 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0