mailer.metrocom.cr has no CNAME records.
Question and response
Question
dig mailer.metrocom.cr. NS
Answer
The response has no answer records.
Authority
metrocom.cr. 300 SOA ns1.cablecolor.hn. administrador.cablecolor.hn. 2026030607 28800 7200 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0