mx2.cegedim-hds.fr has no CNAME records.
Question and response
Question
dig mx2.cegedim-hds.fr. NS
Answer
The response has no answer records.
Authority
cegedim-hds.fr. 3600 SOA ns1.cegedim.fr. hostmaster.cegedim.fr. 2017064256 1200 300 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0