virtualmin.ittelecom.pl has no CNAME records.
Question and response
Question
dig virtualmin.ittelecom.pl. NS
Answer
The response has no answer records.
Authority
ittelecom.pl. 3383 SOA ns1.afraid.org. admin.ittelecom.pl. 2603090002 86400 3600 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0