We are a Shopify app developer and our users rely on us to send various email communications to their customers. Some of these customers opt to use the "hide my email" feature with their Apple ID. Our email client (Sendgrid) shows these emails as delivered but they aren't being received by the client's customers.
Is there anything that can be done to ensure that the private relay emails we receive from our clients are successfully delivered to their customers? We have already completed domain registration with Apple under Certificates, Identifiers & Profiles and followed additional setup documentation from Sendgrid (https://docs.sendgrid.com/ui/account-and-settings/configuring-sign-in-with-apple).