spf.as202591.net has no MX records.
Question and response
Question
dig spf.as202591.net. MX
Answer
The response has no answer records.
Authority
as202591.net. 3600 SOA ns2.as202591.net. support.nefos.nl. 0 86400 900 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0