x2.mailasp.com.tw has no CNAME records.
Question and response
Question
dig x2.mailasp.com.tw. NS
Answer
The response has no answer records.
Authority
mailasp.com.tw. 60 SOA ns.mail2000.com.tw. cloud_se.openfind.com.tw. 2025080701 10800 3600 604800 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0