Configuring DMARC

DMARC standardizes how email receivers perform email authentication using both of the well-known SPF and DKIM mechanisms. It's highly recommended to configure DMARC so that you have better control over the verification of emails originating from your domain. You can check the DMARC configuration of your domain using a service like dmarcian.

For more detail on DMARC, see the DMARC specification or other publicly available documentation on the topic.

Note that DMARC includes alignment checks to ensure the From address domain on an email matches the envelope from field’s domain (that is, smtp.mailfrom). When using an email service such as Oracle Mail Delivery, the smtp.mailfrom matches the domain of the service, not necessarily the sender domain. As such, proper DMARC configuration requires the setup of a Custom Return Path. This redirects the envelope from field to a sender-specific subdomain. The Mail Validation screens report a mismatch between DMARC requirements and mail sender domains if the Custom Return Path hasn't been configured.