mail2.paybox.com has no CNAME records.
Question and response
Question
dig mail2.paybox.com. NS
Answer
The response has no answer records.
Authority
paybox.com. 3600 SOA ns11.paybox.com. admin.paybox.com. 2025121015 1800 600 1296000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0