OpenDNS handling the country code TLD (ccTLD) for Cameroon, ".cm" slightly differently than other ccTLDs. Historically, .cm domains were used as parked domains and in some cases, these parked domains were used to deliver malware.
How does OpenDNS handle this problem?
OpenDNS will return .cm domains when the root server delegates to a name server. However, if an A record is hosted directly on the root .cm server, then OpenDNS will block that domain. This is done because the .cm authoritative name servers used to engage in domain parking for wildcard domains.
If you need to resolve a .cm domain that is currently blocked please add that domain to a allow list.
Alternatively, you can contact firstname.lastname@example.org to have the domain analyzed.