mx1.newtel.cz has no MX records.
Question and response
Question
dig mx1.newtel.cz. MX
Answer
The response has no answer records.
Authority
newtel.cz. 3600 SOA ns1.nameserver.sk. root.nameserver.sk. 2025110702 28800 7200 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0