mx.davonito.com has no NS records.
NS records for this zone are defined at davonito.com.
NS records for this zone are defined at davonito.com.
Question and response
Question
dig mx.davonito.com. NS
Answer
The response has no answer records.
Authority
davonito.com. 3600 SOA dns.davonito.com. hostmaster.davonito.com. 1401321272 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0