relay01.na3.intgdc.com has no MX records.
Question and response
Question
dig relay01.na3.intgdc.com. MX
Answer
The response has no answer records.
Authority
na3.intgdc.com. 60 SOA dns1.p01.nsone.net. hostmaster.nsone.net. 1653485974 600 300 1209600 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0