mail.ct.co.cr has no MX records.
Question and response
Question
dig mail.ct.co.cr. MX
Answer
The response has no answer records.
Authority
ct.co.cr. 84200 SOA ns.ct.co.cr. root.ns.ct.co.cr. 2025063001 7200 7200 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0