spf.omnidesk.io has no MX records.
Question and response
Question
dig spf.omnidesk.io. MX
Answer
The response has no answer records.
Authority
omnidesk.io. 300 SOA ns0.transip.net. hostmaster.transip.nl. 2024102101 86400 1800 2419200 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0