smtp.halloma.com has no CNAME records.
Question and response
Question
dig smtp.halloma.com. NS
Answer
The response has no answer records.
Authority
halloma.com. 1545 SOA a.misconfigured.powerdns.server. hostmaster.halloma.com. 2023111611 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0