mail.vectramail.pl has no CNAME records.
Question and response
Question
dig mail.vectramail.pl. NS
Answer
The response has no answer records.
Authority
vectramail.pl. 4042 SOA ns.multimedia.pl. ns.multimedia.pl. 2025082533 3600 900 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0