rdir.inxmail.com has no NS records.
NS records for this zone are defined at inxmail.com.
NS records for this zone are defined at inxmail.com.
Question and response
Question
dig rdir.inxmail.com. NS
Answer
The response has no answer records.
Authority
inxmail.com. 3600 SOA ns1.dmz.inxmail.de. hostmaster.inxmail.de. 2025120801 3600 1200 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0