mx2.teccloud.com has no CNAME records.
Question and response
Question
dig mx2.teccloud.com. NS
Answer
The response has no answer records.
Authority
teccloud.com. 594 SOA ns1.teccloud.com. dominios.teccloud.com. 2025090301 10800 3600 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0