mx.heatingcoolingsanitarysystems.com has no NS records.
NS records for this zone are defined at heatingcoolingsanitarysystems.com.
NS records for this zone are defined at heatingcoolingsanitarysystems.com.
Question and response
Question
dig mx.heatingcoolingsanitarysystems.com. NS
Answer
The response has no answer records.
Authority
heatingcoolingsanitarysystems.com. 3600 SOA dns.heatingcoolingsanitarysystems.com. hostmaster.heatingcoolingsanitarysystems.com. 1781299385 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0