webmail.acedatasystems.com has no CNAME records.
Question and response
Question
dig webmail.acedatasystems.com. NS
Answer
The response has no answer records.
Authority
acedatasystems.com. 3432 SOA ns-a4.cloud.z.com. postmaster.example.org. 1771819817 3600 600 86400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0