mx02.atman.pl has no CNAME records.
Question and response
Question
dig mx02.atman.pl. NS
Answer
The response has no answer records.
Authority
atman.pl. 2761 SOA dns.atman.pl. noc.atm.com.pl. 2026021602 3600 600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0