smtpout01.fluidparty.com has no CNAME records.
Question and response
Question
dig smtpout01.fluidparty.com. NS
Answer
The response has no answer records.
Authority
fluidparty.com. 3021 SOA ns11.infomaniak.ch. hostmaster.infomaniak.ch. 2025090608 10800 3600 605800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0