What is Apple Private Relay?
When a user signs up using Sign in with Apple and chooses Hide My Email, Apple creates a unique random forwarding address (e.g. random.string@privaterelay.appleid.com) instead of sharing their real Apple ID email.
Messages sent to the relay address are automatically forwarded by Apple to the user’s actual inbox. The user can stop forwarding at any time from their Apple settings. From your perspective, you only ever see and store the relay address.
How Private Relay Affects Senders
- Relay addresses are valid. They are real, deliverable addresses and can be kept on your mailing list.
- Sudden bounces are common. If the user disables forwarding, emails to the relay address will hard bounce. Treat these as permanent failures and suppress them.
- Domain registration is required. Apple recommends registering your sending domain at
register.appleprivaterelay.comto avoid rate limits or delivery issues. - Strong authentication is mandatory. Apple strictly enforces SPF, DKIM, and DMARC alignment. Unauthenticated mail is likely to be rejected or sent to spam.
Implications for Your System
Private Relay addresses make traditional “email as unique identifier” approaches unreliable. One person can have many different relay addresses across services. It is better to use a stable internal user ID as the primary key and treat email addresses as changeable metadata.
For more information on handling bounces and maintaining deliverability with relay services, see the Email Bounce Guide.