mail.d-mail.at has no CNAME records.
Question and response
Question
dig mail.d-mail.at. NS
Answer
The response has no answer records.
Authority
d-mail.at. 3600 SOA ns.udag.de. hostmaster.united-domains.de. 2024092000 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0