José Adorno, 9to5Mac:

One of the features Apple announced during the WWDC21 keynote with iCloud+ was the ability to customize email domains. After two months, you can now do that on iCloud’s beta site.

Here’s how to get started:

• Open beta.icloud.com.
• Click on the Account Settings link just below the Good Morning text.
• Scroll down to the “Custom Email Domain” section and tap the Manage button

The rest depends on your existing setup. Reminder: This is a beta. I’d start off with an unused domain, one that won’t be impacted if Apple decides to make a major change or pull the feature altogether.