spf-mail.ans.ja.net has no MX records.
Question and response
Question
dig spf-mail.ans.ja.net. MX
Answer
The response has no answer records.
Authority
ans.ja.net. 3600 SOA ns10.ja.net. hostmaster.ns10.ja.net. 2023082406 43200 3600 3600000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0