mx1.gaspar.pl has no CNAME records.
Question and response
Question
dig mx1.gaspar.pl. NS
Answer
The response has no answer records.
Authority
gaspar.pl. 300 SOA ns.gaspar.pl. hostmaster.gaspar.pl. 2026021813 7200 3600 2419200 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0