_spf.websupport.sk has no CNAME records.
Question and response
Question
dig _spf.websupport.sk. NS
Answer
The response has no answer records.
Authority
websupport.sk. 782 SOA ns1.websupport.sk. admin.websupport.sk. 1772808768 7200 2048 1048576 2560
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0