Add a new domain and verify that you are the domain admin
You can choose for which specific addresses we should check for spam. If you want filtering for all addresses of that domain, just write @yourdomain.com on the Recipient Address field
Change your domain's MX DNS records to: @ IN MX 10 mx1.oikik.io. and @ IN MX 20 mx2.oikik.io. so we can start filtering your mail!