mail.ocbc.wigitally.com has no CNAME records.
Question and response
Question
dig mail.ocbc.wigitally.com. NS
Answer
The response has no answer records.
Authority
wigitally.com. 463 SOA ns77.domaincontrol.com. dns.jomax.net. 2025121500 28800 7200 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0