mx.maryhorngren.com has no NS records.
NS records for this zone are defined at maryhorngren.com.
NS records for this zone are defined at maryhorngren.com.
Question and response
Question
dig mx.maryhorngren.com. NS
Answer
The response has no answer records.
Authority
maryhorngren.com. 3600 SOA dns.maryhorngren.com. hostmaster.maryhorngren.com. 1120922178 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0