mailrelayus2.kubra.com has no CNAME records.
Question and response
Question
dig mailrelayus2.kubra.com. NS
Answer
The response has no answer records.
Authority
kubra.com. 3600 SOA pdns112.ultradns.com. admin.kubra.com. 2023057493 3600 900 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0