_spf.directtalk.com.br has no CNAME records.
Question and response
Question
dig _spf.directtalk.com.br. NS
Answer
The response has no answer records.
Authority
directtalk.com.br. 28 SOA ns-37.awsdns-04.com. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0