Allow all incoming email messages to a custom email domain on iCloud.com
You can use your iCloud Mail email address as a catch-all address. This allows you to receive all email messages sent to your custom email domain, even if the exact address they were sent to hasn’t already been created.
Note: You must be the domain owner to use this feature. You won’t receive emails sent to addresses that have been previously created for other members of the domain.
On iCloud.com, tap
in the toolbar, then tap Custom Email Domain.Select a domain name, scroll down, then tap Turn On Allow All.
If the domain owner allows all incoming email messages, any email messages that aren’t sent to an active email address go to the domain owner’s inbox. If this setting isn’t turned on, those email messages are returned to the sender.
Note: Email messages sent to deleted email addresses are automatically returned to the sender.