ns2.cpi.ad.jp has no MX records.
Question and response
Question
dig ns2.cpi.ad.jp. MX
Answer
The response has no answer records.
Authority
cpi.ad.jp. 300 SOA ns0.cpi.ad.jp. hostmaster.cpi.ad.jp. 2026022501 3600 900 3600000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0