mx02.htp-tel.de has no NS records.
NS records for this zone are defined at htp-tel.de.
NS records for this zone are defined at htp-tel.de.
Question and response
Question
dig mx02.htp-tel.de. NS
Answer
The response has no answer records.
Authority
htp-tel.de. 3600 SOA ns.htp-tel.de. domainmaster.htp.net. 2026032200 43200 7200 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0