mx.rozhled.cz has no CNAME records.
Question and response
Question
dig mx.rozhled.cz. NS
Answer
The response has no answer records.
Authority
rozhled.cz. 1332 SOA ns.rozhled.cz. admin.rozhled.cz. 2025112101 3600 900 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0