mail.mtsnet.ru has no NS records.
NS records for this zone are defined at mtsnet.ru.
NS records for this zone are defined at mtsnet.ru.
Question and response
Question
dig mail.mtsnet.ru. NS
Answer
The response has no answer records.
Authority
mtsnet.ru. 900 SOA ns2.mts.ru. dns.mts.ru. 2026030501 10800 1800 604800 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0