Generate a DKIM key pair (public and private keys). This can usually be done through your email service provider or using a DKIM generator tool. Publish the public key in your domain's DNS records. This involves adding a TXT record with the DKIM selector and public key. Configure your email server to sign outgoing emails with the DKIM private key. Test your DKIM setup using tools like DKIMCore or MXToolbox to ensure everything is configured correctly.