mx1.datahotel.ne.jp has no CNAME records.
Question and response
Question
dig mx1.datahotel.ne.jp. NS
Answer
The response has no answer records.
Authority
datahotel.ne.jp. 3600 SOA zns01.datahotel.ne.jp. hostmaster.datahotel.ne.jp. 2026030501 1800 600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0