_spf.sendnode.com has no CNAME records.
Question and response
Question
dig _spf.sendnode.com. NS
Answer
The response has no answer records.
Authority
sendnode.com. 360 SOA a.ns14.net. domainadmin.w3work.de. 2025120912 43200 7200 1209600 360
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0