mail4.asipay.com has no CNAME records.
Question and response
Question
dig mail4.asipay.com. NS
Answer
The response has no answer records.
Authority
asipay.com. 3044 SOA ns6a.savvis.net. dns-admin.centurylink.com. 2220507020 3600 1800 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0