mx.quereven.com has no NS records.
NS records for this zone are defined at quereven.com.
NS records for this zone are defined at quereven.com.
Question and response
Question
dig mx.quereven.com. NS
Answer
The response has no answer records.
Authority
quereven.com. 3600 SOA dns.quereven.com. hostmaster.quereven.com. 1372312748 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0