phx1.oracleemaildelivery.com has no MX records.
Question and response
Question
dig phx1.oracleemaildelivery.com. MX
Answer
The response has no answer records.
Authority
phx1.oracleemaildelivery.com. 1800 SOA ns1.p01.dynect.net. hostmaster.dyndns.com. 735295 3600 600 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0