mail.n2nconnect.com has no CNAME records.
Question and response
Question
dig mail.n2nconnect.com. NS
Answer
The response has no answer records.
Authority
n2nconnect.com. 926 SOA fiona.ns.cloudflare.com. dns.cloudflare.com. 2397349194 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0