Apple recently announced that it plans to integrate the email domain names used by the "Sign in with Apple" and iCloud+ "Hide My Email" functions into the new private.icloud.com domain name.
Currently, the relay email address generated by Sign in with Apple uses the privaterelay.appleid.com domain name, while iCloud+'s Hide My Mail feature uses the icloud.com domain name. According to instructions issued by Apple to developers, these two types of transit mailboxes will be unified to addresses with private.icloud.com as the domain name starting this summer. In the future, newly generated transit mailboxes will come from this private domain name.
Apple stated that existing email addresses using the old domain names will continue to be valid, relevant emails will be forwarded normally, and services will not be interrupted due to this adjustment. There is no setup or action required on the part of the user, and Sign in with Apple and Hide My Email will continue to work the same way they did, with the new private domain taking over email address assignment and forwarding behind the scenes.
However, Apple also reminds developers that they need to ensure the account system, email verification logic and email whitelist configuration of their applications and websites as soon as possible, and include the private.icloud.com domain name into the allowed list. For enterprises and third-party email service providers that rely on email services, they may also need to update domain name-based filtering rules, bounce/suppression lists, or routing policies to avoid accidentally blocking emails in transit mailboxes under Apple's new domain name.
Apple's adjustment is seen as a structural consolidation of the anonymous relay mailbox system: it not only reduces maintenance costs technically, simplifies domain name management, but also strengthens the unified image of iCloud private domain names at the product level. With the activation of unified domain names, third-party compatibility and email delivery strategies around "Sign in with Apple" and "Hide My Email" are bound to usher in a new round of adaptation and adjustment.