_spfmailers.eventkingdom.com has no CNAME records.
Question and response
Question
dig _spfmailers.eventkingdom.com. NS
Answer
The response has no answer records.
Authority
eventkingdom.com. 3600 SOA ns.udag.de. hostmaster.united-domains.de. 2025082747 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0