ns1.mexicosystem.com has no MX records.
Question and response
Question
dig ns1.mexicosystem.com. MX
Answer
The response has no answer records.
Authority
mexicosystem.com. 86400 SOA ns1.mexicosystem.com. servers.privatednsorg.com. 2026012800 86400 7200 1600000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0