mx4.saas.lu has no NS records.
NS records for this zone are defined at saas.lu.
NS records for this zone are defined at saas.lu.
Question and response
Question
dig mx4.saas.lu. NS
Answer
The response has no answer records.
Authority
saas.lu. 86400 SOA ns1.eurodns.com. hostmaster.eurodns.com. 2026022300 43200 7200 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0