mx.fuse.net has no NS records.
NS records for this zone are defined at fuse.net.
NS records for this zone are defined at fuse.net.
Question and response
Question
dig mx.fuse.net. NS
Answer
The response has no answer records.
Authority
fuse.net. 794 SOA ns1.fuse.net. hostmaster.fuse.net. 3661 10800 3600 2419200 900
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0