spf-01.ricoh.co.jp has no MX records.
Question and response
Question
dig spf-01.ricoh.co.jp. MX
Answer
The response has no answer records.
Authority
ricoh.co.jp. 300 SOA ns1.jp.ricoh.com. postmaster.ns1.jp.ricoh.com. 2026030602 3600 1800 604800 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0