Every .dk domain whose DKIM selector is a CNAME to selector1-xnskdehjbjergholme5tb89a-dk0m1b1be._domainkey.jfmedier.onmicrosoft.com — the mail platform that holds the signing key. Domains sharing a DKIM target are onboarded to the same provider. Data comes from our own scanners, which re-resolve every .dk domain in the zone roughly once a week.