ns.nrnet.com has no MX records.
Question and response
Question
dig ns.nrnet.com. MX
Answer
The response has no answer records.
Authority
nrnet.com. 1800 SOA ns.nr.net. hostmaster.nr.net. 2023112157 3600 600 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0