If your web or mobile app supports “Sign in with Apple” as a login method, this means that iOS users can log in with a private, dedicated email address (like ‘a1b2c3@privaterelay.appleid.com’). When you send email to that address, Apple will forward it to the email address associated with their Apple ID.

For this to work successfully, you must register your domain with Apple, as explained here in Apple’s documentation.

This ensures that If there’s a problem causing these emails to fail, or the user no longer wants to receive your emails, Apple can notify you of the bounce.

Tip: If you send Intercom emails from your own domain, skip step 1, as you’ll find your Return-Path address in your own email setup.

If you send your emails from Intercom’s standard email address, you can find the domain under Settings > Channels > Email > Sender email addresses.

Simply add "rp." at the start of your Intercom domain, and this is your Return-Path address. For example, rp.examply.intercom-mail.com.

If you opted to send using your own domain, find your domain under Settings > Channels > Email > Domains and use the Return-Path address that starts with "rp".

Add this to the Domains section of “Certificates, Identifiers & Profiles” in your Apple developer settings.

And that’s it. 👌

With the Return-Path configured in your Apple developer settings, Apple will be able to notify you in the event that one of your emails fails to reach its recipient.