mail.metrocom.com.pa has no CNAME records.
Question and response
Question
dig mail.metrocom.com.pa. NS
Answer
The response has no answer records.
Authority
metrocom.com.pa. 3396 SOA ns1.metrocom.com.pa. administrador.metrocom.com.pa. 2026022101 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0