hfmail2.happyfox.com has no CNAME records.
Question and response
Question
dig hfmail2.happyfox.com. NS
Answer
The response has no answer records.
Authority
happyfox.com. 522 SOA lisa.ns.cloudflare.com. dns.cloudflare.com. 2397944493 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0