smtp4.mtficore.net has no NS records.
NS records for this zone are defined at mtficore.net.
NS records for this zone are defined at mtficore.net.
Question and response
Question
dig smtp4.mtficore.net. NS
Answer
The response has no answer records.
Authority
mtficore.net. 86202 SOA dns1.ficolo.net. hostmaster.ficolo.net. 2020051901 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0