mh1.omnitel.net has no MX records.
Question and response
Question
dig mh1.omnitel.net. MX
Answer
The response has no answer records.
Authority
omnitel.net. 1800 SOA cash.ns.cloudflare.com. dns.cloudflare.com. 2397149827 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0