Apple’s proposed changes to a privacy feature that allows subscribers to conceal their real email addresses when signing up for online services could make it easier for apps and websites to identify and block anonymous registrations.

The feature, known as Hide My Email, is available to iCloud+ subscribers and generates unique @icloud.com email addresses that forward messages to a user’s actual inbox. Currently, these randomly generated addresses are difficult to distinguish from standard Apple email accounts because both use the same @icloud.com domain, helping users maintain anonymity when creating accounts online.

In a note to developers on Monday, Apple disclosed that it will, in the coming weeks, shift its anonymously generated email addresses from the standard @icloud.com domain to a new @private.icloud.com domain.

The change could make it easier for apps and websites to identify users relying on the privacy feature and potentially restrict anonymous account registrations.

Apple said existing Hide My Email addresses will remain fully functional and continue forwarding messages without disruption.

However, the company advised app developers and email service providers to update their filtering systems to ensure emails sent to users of the feature are delivered properly.

The planned change has drawn criticism from some Apple users on Reddit, who argued that moving anonymous addresses to a distinct @private.icloud.com domain could make the privacy feature less useful by making it easier for websites and apps to identify and potentially reject users seeking to keep their email addresses private.

Apple has not publicly explained the reason for the change.