What is Apple Private Relay?

Some recipients use Sign in with Apple, which masks their personal email behind a Private Relay address (e.g. @privaterelay.appleid.com).

Common Bounce Messages

When sending to these addresses, you may see elevated bounce rates or specific bounce messages such as:

• blocked by receiver (1850)
• relay not permitted for this domain

These bounces are generated by Apple's relay servers before the email reaches the end user.

Why Does This Happen?

Apple's Private Email Relay Service only accepts mail from registered sending domains. If a client's sending domain has not been registered under their Apple Developer account, Apple's servers will automatically reject all messages routed through the relay. This is an Apple-side restriction, not an issue with Taguchi's infrastructure or authentication setup.

Example Scenario

A campaign sent via Taguchi to @privaterelay.appleid.com addresses experiences high bounce rates. Other domains (e.g. Gmail, Outlook, standard @icloud.com) deliver successfully. SPF/DKIM pass validation.

The bounce reason appears as "blocked by receiver (1850)". This pattern confirms that Apple's Private Relay filter is blocking delivery.

How to Resolve

To resolve, register your sending domains with Apple's Private Email Relay Service.

Apple documentation: 🔗 Configure Private Email Relay Service – Apple Developer

Once the registration is complete and verified, Apple will allow relay messages to pass through to the user's inbox.

Continue to authenticate all sends with valid SPF, DKIM, and DMARC records.

Need More Help?

If you encounter any issues regarding High Bounce Rates, you may open a support ticket for assistance.

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