ns.gtdinternet.com has no MX records.
Question and response
Question
dig ns.gtdinternet.com. MX
Answer
The response has no answer records.
Authority
gtdinternet.com. 300 SOA ns.gtdinternet.com. operaciones.gtdinternet.com. 2026021301 7200 360 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0