mx1.teccloud.com has no CNAME records.
Question and response
Question
dig mx1.teccloud.com. NS
Answer
The response has no answer records.
Authority
teccloud.com. 600 SOA ns1.teccloud.com. dominios.teccloud.com. 2025090301 10800 3600 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0