mx.centreorl.com has no NS records.
NS records for this zone are defined at centreorl.com.
NS records for this zone are defined at centreorl.com.
Question and response
Question
dig mx.centreorl.com. NS
Answer
The response has no answer records.
Authority
centreorl.com. 3600 SOA dns.centreorl.com. hostmaster.centreorl.com. 1986922971 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0