spf.tds.de has no NS records.
NS records for this zone are defined at tds.de.
NS records for this zone are defined at tds.de.
Question and response
Question
dig spf.tds.de. NS
Answer
The response has no answer records.
Authority
tds.de. 300 SOA ns1.manage-now.de. security.tds.de. 2025120701 21600 3600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0