mail.toya.com.pl has no CNAME records.
Question and response
Question
dig mail.toya.com.pl. NS
Answer
The response has no answer records.
Authority
toya.com.pl. 10800 SOA dns.toya.net.pl. root.toya.net.pl. 2026020409 7200 3600 1209600 172800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0