mail.office365.com has no NS records.
NS records for this zone are defined at office365.com.
NS records for this zone are defined at office365.com.
Question and response
Question
dig atm.outlook.mira.tm.svc.cloud.microsoft. NS
Answer
The response has no answer records.
Authority
cloud.microsoft. 60 SOA ns1-33.azure-dns.com. azuredns-hostmaster.microsoft.com. 1 3600 120 2419200 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0