mail.niig.com.np has no CNAME records.
Question and response
Question
dig mail.niig.com.np. NS
Answer
The response has no answer records.
Authority
niig.com.np. 300 SOA dns1.niig.com.np. noc.niig.com.np. 2022110313 360 1800 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0