smtp.jobaffinity.fr has no CNAME records.
Question and response
Question
dig smtp.jobaffinity.fr. NS
Answer
The response has no answer records.
Authority
jobaffinity.fr. 934 SOA harlan.ns.cloudflare.com. dns.cloudflare.com. 2397647571 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0