spf1.mufg.jp has no MX records.
Question and response
Question
dig spf1.mufg.jp. MX
Answer
The response has no answer records.
Authority
mufg.jp. 3600 SOA dns01.mufg.jp. postmaster.mufg.jp. 2026022100 10800 3600 604800 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0