mail.endstream.com has no NS records.
NS records for this zone are defined at endstream.com.
NS records for this zone are defined at endstream.com.
Question and response
Question
dig mail.endstream.com. NS
Answer
The response has no answer records.
Authority
endstream.com. 3600 SOA ns.endstream.net. hostmaster.endstream.net.endstream.com. 2026011201 14400 900 1800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0