Add or remove people sharing a custom email domain on iCloud.com

If you added a custom email domain to iCloud Mail, you can share it with up to five other people. Each person you share with needs to have an Apple ID, have two-factor authentication turned on, and have a primary iCloud Mail email address.

Note: Only the domain owner can add and remove people.

Add a person

On iCloud.com, click in the toolbar, then click Custom Email Domain.
Select the domain you want to share.
Click Add People, enter the phone number or email address of the person you want to add, then click Continue.
Note: You can add someone who is not part of your Family Sharing group if they subscribe to iCloud+. When they accept the invitation, they are added to the domain.
If you add someone and they have an existing email address at the domain, you can assign it to them. Type the email address in the field below their name. After you finish adding email addresses, click “Add email address(es)”.

Remove a person

When you remove a person from your domain, any email addresses they created are deleted and subsequent emails sent to those addresses are returned to the sender.

However, any emails they sent and received before you removed them remain in their iCloud Mail account.

On iCloud.com, click in the toolbar, then click Custom Email Domain.
Select the domain you want to remove someone from.
Click next to their name, then click Remove.

Helpful?

iCloud User Guide

Add or remove people sharing a custom email domain on iCloud.com

Add a person

Remove a person