mkt.relay.amadeus.net has no NS records.
NS records for this zone are defined at amadeus.net.
NS records for this zone are defined at amadeus.net.
Question and response
Question
dig mkt.relay.amadeus.net. NS
Answer
The response has no answer records.
Authority
amadeus.net. 600 SOA mucdns01.amadeus-dns.com. nicadmin.amadeus.com. 2008030532 3600 1200 2592000 600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0