spf.dondominio.com has no CNAME records.
Question and response
Question
dig spf.dondominio.com. NS
Answer
The response has no answer records.
Authority
dondominio.com. 60 SOA ns1.dondominio.com. dnsadmin.dondominio.com. 2026030500 10800 1800 691200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0