ns1.jetsmtp.net has no CNAME records.
Question and response
Question
dig ns1.jetsmtp.net. NS
Answer
The response has no answer records.
Authority
jetsmtp.net. 1800 SOA melina.ns.cloudflare.com. dns.cloudflare.com. 2398200577 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0