returnpath.zivver.com has no CNAME records.
Question and response
Question
dig returnpath.zivver.com. NS
Answer
The response has no answer records.
Authority
zivver.com. 456 SOA dora.ns.cloudflare.com. dns.cloudflare.com. 2397112855 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0