mx.terabit.net.id has no CNAME records.
Question and response
Question
dig mx.terabit.net.id. NS
Answer
The response has no answer records.
Authority
terabit.net.id. 9953 SOA ns1.terabit.net.id. root.ns1.terabit.net.id. 2026020512 7200 3600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0