Starting with iOS 15, iPadOS 15, and macOS Monterey, users with a paid iCloud+ storage plan can personalize their iCloud email address with a custom domain name, such as johnny@appleseed.com, and the feature is now available in beta.
iCloud+ subscribers interested in setting up a custom email domain can visit the beta.icloud.com website, select "Account Settings" under their name, and select "Manage" under "Custom Email Domain." Users can send and receive email with up to five custom domains, while family members can each have up to three email addresses per domain.
After entering a custom domain on the iCloud website, users can add email addresses that they currently use with the domain. Users can also create new email addresses after they have finished setting up the domain with iCloud, according to Apple. Note that any custom email addresses must not be in use with another Apple ID.
For those who missed the announcement back at WWDC in June, iCloud+ is Apple's new branding for paid iCloud storage combined with new features like iCloud Private Relay and Hide My Email. iCloud+ features are included with iCloud storage plans at no additional cost, with prices remaining set at $0.99 per month for 50GB of storage, $2.99 per month for 200GB of storage, or $9.99 per month for 2TB of storage in the United States.
The ability to use a custom email address for iCloud is not to be confused with Hide My Email, a separate iCloud+ feature that allows users to create unique, random email addresses that forward to their personal inbox so they can send and receive email without having to share their real email address.
Source: Macrumors