mail.karoo.kcom.com has no CNAME records.
Question and response
Question
dig mail.karoo.kcom.com. NS
Answer
The response has no answer records.
Authority
karoo.kcom.com. 5500 SOA ibex.kcom.com. hostmaster.kcom.com. 2025081201 28800 7200 604800 28800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0