mx.soundoftheseason.com has no NS records.
NS records for this zone are defined at soundoftheseason.com.
NS records for this zone are defined at soundoftheseason.com.
Question and response
Question
dig mx.soundoftheseason.com. NS
Answer
The response has no answer records.
Authority
soundoftheseason.com. 3600 SOA dns.soundoftheseason.com. hostmaster.soundoftheseason.com. 1489707379 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0