mxout01.prod.mail.s1.fti.net has no CNAME records.
Question and response
Question
dig mxout01.prod.mail.s1.fti.net. NS
Answer
The response has no answer records.
Authority
s1.fti.net. 1800 SOA ns1.fti.net. hostmaster.orangeportails.net. 2025111700 1800 900 1814400 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0