ns4.mailspamprotection.com has no MX records.
Question and response
Question
dig ns4.mailspamprotection.com. MX
Answer
The response has no answer records.
Authority
mailspamprotection.com. 86400 SOA ns-cloud-c1.googledomains.com. msi200.ms200.com. 2021122801 86400 7200 3600000 86400
Additional
. 0 OPT ; payload 512, xrcode 0, version 0, flags 0