mail.kki.pl has no CNAME records.
Question and response
Question
dig mail.kki.pl. NS
Answer
The response has no answer records.
Authority
kki.pl. 4459 SOA kki.pl. hostmaster.kkibci.pl. 2025111700 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0