mxr3.enom.com has no MX records.
Question and response
Question
dig mxr3.enom.com. MX
Answer
The response has no answer records.
Authority
enom.com. 120 SOA ns1.enom.com. hostmaster.enom.com. 1771792757 43200 120 604800 120
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0