mail.trusts.cpcnet.com has no CNAME records.
Question and response
Question
dig mail.trusts.cpcnet.com. NS
Answer
The response has no answer records.
Authority
trusts.cpcnet.com. 600 SOA ns1.hk.net. hostmaster.cpcnet-hk.com. 2015040101 10800 3600 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0