Apex domains cannot have CNAME records.
Question and response
Question
dig smadm.pl. NS
Answer
smadm.pl. 5 NS dns1.smadm.pl.
smadm.pl. 5 NS dns2.smadm.pl.
Authority
The response has no authority records.
Additional
dns1.smadm.pl. 5 A 212.180.241.247
dns2.smadm.pl. 5 A 212.180.241.206
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0