mail4.jobdiva.com has no CNAME records.
Question and response
Question
dig mail4.jobdiva.com. NS
Answer
The response has no answer records.
Authority
jobdiva.com. 1800 SOA alice.ns.cloudflare.com. dns.cloudflare.com. 2396650137 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0