smtp-ft.paybox.com has no CNAME records.
Question and response
Question
dig smtp-ft.paybox.com. NS
Answer
The response has no answer records.
Authority
paybox.com. 2294 SOA ns11.paybox.com. admin.paybox.com. 2025121015 1800 600 1296000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0