mail.fad.uncu.edu.ar has no NS records.
NS records for this zone are defined at fad.uncu.edu.ar.
NS records for this zone are defined at fad.uncu.edu.ar.
Question and response
Question
dig fadmail.fad.uncu.edu.ar. NS
Answer
The response has no answer records.
Authority
fad.uncu.edu.ar. 300 SOA ns1.fad.uncu.edu.ar. root.fad.uncu.edu.ar. 202312199 300 86400 2419200 604800
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0