By default all emails sent from SpeedAdmin are DKIM signed. The DKIM is signed up against the speedadmin.dk domain.
If you have set up sending of email from your own domain instead of the default speedadmin.dk, you might also want to ensure the DKIM signing is aligned up against the domain of the From address and your SPF record.
If so, before activating it in SpeedAdmin, you must setup a CNAME record on your domain, that redirects DKIM validators from your domain to the SpeedAdmin domain. For example:
speedadmin2._domainkey.[yourDomainHere.com] must point to speedadmin2._domainkey.speedadmin.dk