add email addresses to family on icloud custom domain

Hello njwetsu,

Thanks for choosing the Apple Support Communities. it sounds liek you want to personalize your custom emails. We have a few steps that may help.

Personalize iCloud Mail with a custom email domain and share with others - Apple Support

"When you subscribe to iCloud+, you can personalize your iCloud Mail address with a custom domain name and invite friends or family members to use the same domain with their iCloud Mail accounts.

Note: Custom Email Domain isn’t available in all countries or regions.

Send and receive email from a custom email domain

You can use your iPhone, iPad, iPod touch, and iCloud.com to add an email domain and share it with up to five friends or family members. You can either purchase a new domain or move one you already own to iCloud.

If you already have email addresses at a domain, you can configure them and assign them to others during setup. Otherwise, everyone can create email addresses later. Each person can have up to three active email addresses per domain. The domain owner can also decide to accept messages sent to addresses that aren’t actively set up with the domain.

Because your custom email domain uses iCloud Mail, it works in the same way. When you configure or create a new address, you can automatically send and receive email from that address in Mail anywhere you have iCloud Mail turned on, including your iPhone, iPad, iPod touch, and Mac. You can also access your mail in Outlook on a Windows computer and in a web browser at iCloud.com.

Note: Mail stored in iCloud counts toward your iCloud storage. If you run out of iCloud storage space, you won’t be able to receive new messages at your custom email addresses until you make more storage space available."

We hope this helps.

Cheers!