cdxmailin01.datev.de has no NS records.
NS records for this zone are defined at datev.de.
NS records for this zone are defined at datev.de.
Question and response
Question
dig cdxmailin01.datev.de. NS
Answer
The response has no answer records.
Authority
datev.de. 600 SOA ns01.datev.de. dnsmaster.datev.de. 2603030912 21600 3600 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0