mail.freewebworld.fr has no CNAME records.
Question and response
Question
dig mail.freewebworld.fr. NS
Answer
The response has no answer records.
Authority
freewebworld.fr. 4493 SOA dns200.anycast.me. hostmaster.mail.freewebworld.fr. 2026022600 7200 3600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0