mail.cubepasses.com has no NS records.
NS records for this zone are defined at cubepasses.com.
NS records for this zone are defined at cubepasses.com.
Question and response
Question
dig mail.cubepasses.com. NS
Answer
The response has no answer records.
Authority
cubepasses.com. 1800 SOA edward.ns.cloudflare.com. dns.cloudflare.com. 2398004463 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0