smtp.antic.cm has no CNAME records.
Question and response
Question
dig smtp.antic.cm. NS
Answer
The response has no answer records.
Authority
antic.cm. 10800 SOA dns1.antic.cm. admin.antic.cm. 2025081542 3600 1800 1209656 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0