mx.dingfeng.eu has no CNAME records.
Question and response
Question
dig mx.dingfeng.eu. NS
Answer
The response has no answer records.
Authority
dingfeng.eu. 2510 SOA dns.technorail.com. hostmaster.dingfeng.eu. 2026012104 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0