_spf2.americanet.com.br has no CNAME records.
Question and response
Question
dig _spf2.americanet.com.br. NS
Answer
The response has no answer records.
Authority
americanet.com.br. 10800 SOA cp1.americanet.com.br. postmaster.americanet.com.br. 2026022803 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0