Apex domains cannot have CNAME records.
Question and response
Question
dig cp04.msdata.at. NS
Answer
cp04.msdata.at. 5 NS dns2.msdata.at.
cp04.msdata.at. 5 NS dns1.msdata.at.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0