mx.itwkf.com has no NS records.
NS records for this zone are defined at itwkf.com.
NS records for this zone are defined at itwkf.com.
Question and response
Question
dig mx.itwkf.com. NS
Answer
The response has no answer records.
Authority
itwkf.com. 3600 SOA dns.itwkf.com. hostmaster.itwkf.com. 1407301246 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0