smtp.blacom.net has no MX records.
Question and response
Question
dig smtp.blacom.net. MX
Answer
The response has no answer records.
Authority
blacom.net. 3600 SOA dns1.internetcomunicate.mx. antonio.internetcomunicate.mx. 2026014855 1800 900 2419200 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0