mx.web2010.com has no NS records.
NS records for this zone are defined at web2010.com.
NS records for this zone are defined at web2010.com.
Question and response
Question
dig mx.web2010.com. NS
Answer
The response has no answer records.
Authority
web2010.com. 1 SOA ns.web2010.com. root.web2010.com. 200506080 10800 3600 604800 1
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0