mx.wanhong5.com has no CNAME records.
Question and response
Question
dig mx.wanhong5.com. NS
Answer
The response has no answer records.
Authority
wanhong5.com. 2006 SOA dns.wanhong5.com. hostmaster.wanhong5.com. 1816077825 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0