zeus.eanet.cz has no MX records.
Question and response
Question
dig zeus.eanet.cz. MX
Answer
The response has no answer records.
Authority
eanet.cz. 1800 SOA zeus.eanet.cz. dnsadm.zeus.eanet.cz. 2017062903 3600 3600 7200 3600
Additional
. 0 OPT ; payload 512, xrcode 0, version 0, flags 0