mx.itwkf.com has no CNAME records.
Question and response
Question
dig mx.itwkf.com. NS
Answer
The response has no answer records.
Authority
itwkf.com. 3474 SOA dns.itwkf.com. hostmaster.itwkf.com. 1407301246 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0