spf01.arorua.net has no MX records.
Question and response
Question
dig spf01.arorua.net. MX
Answer
The response has no answer records.
Authority
arorua.net. 300 SOA ns1.x.recruit.co.jp. postmaster.x.recruit.co.jp. 2025111001 10800 3600 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0