smtp.lis.eu has no NS records.
NS records for this zone are defined at lis.eu.
NS records for this zone are defined at lis.eu.
Question and response
Question
dig smtp.lis.eu. NS
Answer
The response has no answer records.
Authority
lis.eu. 43200 SOA rz-ns-01.winsped.de. administrator.lis.eu. 2020122498 21600 21600 864000 43200
Additional
. 0 OPT ; payload 4000, xrcode 0, version 0, flags 0