nic.neustar has no MX records.
Question and response
Question
dig nic.neustar. MX
Answer
The response has no answer records.
Authority
nic.neustar. 900 SOA ns1.dns.nic.neustar. admin.tldns.godaddy. 1772394357 1800 300 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0