mx1.spamscan.xetnet.com has no NS records.
NS records for this zone are defined at xetnet.com.
NS records for this zone are defined at xetnet.com.
Question and response
Question
dig mx1.spamscan.xetnet.com. NS
Answer
The response has no answer records.
Authority
xetnet.com. 600 SOA ns-1.xetnet.com. hostmaster.xetnet.com. 2026030600 600 1800 1209600 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0