How is the outbound email flow in case of "Reject" policy?

How is the outbound email flow in case of "Reject" policy?

Under the "Reject" policy, the receiver completely prevents any unqualified email from reaching the recipient. With this enabled, only an email that is verified as 100% being signed by your domain will even have a chance at reaching the inbox. Any email that does not pass is blackholed— not bounced—so there’s no way to catch false positives.