mail.fst-pay.net has no MX records.
Question and response
Question
dig mail.fst-pay.net. MX
Answer
The response has no answer records.
Authority
fst-pay.net. 60 SOA dns101.ovh.net. tech.ovh.net. 2024121609 86400 3600 3600000 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0