spf.mailhy.com has no MX records.
Question and response
Question
dig spf.mailhy.com. MX
Answer
The response has no answer records.
Authority
mailhy.com. 86400 SOA ns1.mailhy.com. Postmaster.mailhy.com. 343569443 10800 3600 172800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0