www.nic.cr has no MX records.
Question and response
Question
dig www.nic.cr. MX
Answer
The response has no answer records.
Authority
nic.cr. 300 SOA dns.nic.cr. ti.nic.cr. 2026020528 14400 7200 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0