mail.cs361demo.awk.jp has no CNAME records.
Question and response
Question
dig mail.cs361demo.awk.jp. NS
Answer
The response has no answer records.
Authority
cs361demo.awk.jp. 438 SOA ns.cs361demo.awk.jp. brs-support.xbit.jp. 2026020102 300 60 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0