mail.skybw-data.center has no CNAME records.
Question and response
Question
dig mail.skybw-data.center. NS
Answer
The response has no answer records.
Authority
skybw-data.center. 5604 SOA a.regfish-ns.net. dns.regfish-ns.net. 1750924624 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0