mail.kolaszewski.com has no CNAME records.
Question and response
Question
dig mail.kolaszewski.com. NS
Answer
The response has no answer records.
Authority
kolaszewski.com. 1991 SOA ns1.seohost.pl. hostmaster.kolaszewski.com. 2025120800 2000 3600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0