“Unknown” results within DMARC indicate that 250ok was unable to resolve the reverse DNS of the associated IP.
Because DNS is sometimes prone to failure, this is not an uncommon cause of these results.
Infrastructure-related issues could be another potential cause of this problem. 250ok recommends ensuring that all IP’s have a PTR record, and that an rDNS record is present for that PTR.
Lastly, this could signal that the domain is potentially being used to send junk mail.
Contact firstname.lastname@example.org with any questions about “Unknown” results in 250ok DMARC.