mail1.filteredmx.net has no NS records.
NS records for this zone are defined at filteredmx.net.
NS records for this zone are defined at filteredmx.net.
Question and response
Question
dig mail1.filteredmx.net. NS
Answer
The response has no answer records.
Authority
filteredmx.net. 3600 SOA ns1.kgix.com. sysadmin.filteredmx.com. 2020062500 1200 1800 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0