mail.vcsk.hu has no CNAME records.
Question and response
Question
dig mail.vcsk.hu. NS
Answer
The response has no answer records.
Authority
vcsk.hu. 3600 SOA ns.vcsk.hu. postmaster.mail.vcsk.hu. 2015112605 3600 7200 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0