mx0.msk.ru.itoolabs.net has no NS records.
NS records for this zone are defined at msk.ru.itoolabs.net.
NS records for this zone are defined at msk.ru.itoolabs.net.
Question and response
Question
dig mail1.msk.ru.itoolabs.net. NS
Answer
The response has no answer records.
Authority
msk.ru.itoolabs.net. 600 SOA dns1.itoolabs.net. noc.itoolabs.net. 2026020501 28800 7200 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0