_spf.cloudkey.pt has no CNAME records.
Question and response
Question
dig _spf.cloudkey.pt. NS
Answer
The response has no answer records.
Authority
cloudkey.pt. 45 SOA ns1.eventkey.pt. hostmaster.cloudkey.pt. 2026022700 3600 600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0