mail.dns1.de has no NS records.
NS records for this zone are defined at dns1.de.
NS records for this zone are defined at dns1.de.
Question and response
Question
dig mail.dns1.de. NS
Answer
The response has no answer records.
Authority
dns1.de. 900 SOA anycast.regdns1.de. hostmaster.partnergate.com. 2026021900 28800 7200 604800 900
Additional
. 0 OPT ; payload 1400, xrcode 0, version 0, flags 0