_spf.free.org has no CNAME records.
Question and response
Question
dig _spf.free.org. NS
Answer
The response has no answer records.
Authority
free.org. 3577 SOA ns0.free.org. hostmaster.free.org. 2026022001 28800 3600 691200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0