mx.oru.edu.gr has no NS records.
NS records for this zone are defined at oru.edu.gr.
NS records for this zone are defined at oru.edu.gr.
Question and response
Question
dig mx.oru.edu.gr. NS
Answer
The response has no answer records.
Authority
oru.edu.gr. 1800 SOA faye.ns.cloudflare.com. dns.cloudflare.com. 2397674482 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0