mailserv.desnet.id has no CNAME records.
Question and response
Question
dig mailserv.desnet.id. NS
Answer
The response has no answer records.
Authority
desnet.id. 1000 SOA hosting.ptdes.net. dnsadmin.ptdes.net. 2026020901 3600 540 48000 24000
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0