Use iCloud+ Custom Email Domain with Outlook for Windows

I think I found the solution. To re-state the issue:

Apple iCloud+ was used to create a custom domain for email.

Example: ******@customdomain.com

Apple forces you to create an @icloud address when configuring the custom domain.

Example: ******@icloud.com

Setting up apple ios and mail on the mac understand the trickery and work perfectly. You send an email, and the email comes FROM ******@customdomain.com

Outlook does NOT work so well. Emails come from ******@icloud.com. On the latest Outlook 365 (for me, it's version 2311, Build 17029), there is limited options to configure. It's trying to do everything for you. There are two built in ways to deal with this:

1. Go into the account settings, you can change the "reply to address" to be ******@customdomain.com
2. While sending an email, you can click the drop down on the FROM button and you can type in ******@customdomain.com

The result of each of the actions is the same. The emails that are received this way will show they came from ******@icloud.com <on behalf of ******@customdomain.com>. If the recipient hits reply, it will indeed go back to ******@customdomain.com, but there are numerous use cases where the FROM field is read by something automated so the Reply-To address is irrelevant.

I tried something tonight and it seems to be working to solve this. Open the registry editor, and navigate to:

HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Profiles&lt;your profile name>

Press F3 and search for your icloud address (******@icloud.com)

You should see a match further down in this same branch (make sure it is). Look for a field called "Email" and the value will be your icloud address (@icloud.com). Edit this field to be your custom domain address (@customdomain.com).

Close outlook if it is open and re-open it. Emails should work normally now and the from address should be your custom domain.

I totally agree, as long as we can not use an icloud+ domain on Outlook Mac, i will not be using this product.

Hi Crispin, when you send an email in Outlook, the sender field is a dropdown list. One option is to select "other email address". Just enter the external domain email address you want to send from, and Outlook will remember it. The next time you want to send from this email address, it will be available in the dropdown.

My wife uses Outllook 365. I set up four separate Outlook inboxes for her @iCloud email address plus her three external domain addresses. When she replies to an email in an external domain inbox, the sender field shows her @iCloud email address. All she has to do is pick the correct external domain email address from the dropdown list before sending.

If you don't want to set up separate Outlook inboxes for all your iCloud email accounts, all emails should show up in the @iCloud.com account that was used to configure the external domain email.

Ernst

Hey There, I tested this and it does not work. When doing this it won't send the email and it displays this error: "You don't have permission to send the message on behalf of the specified user."

Not my experience, works well here except aliases are not automatically determined by the Inbox being used as it is on the Mac. Do you have your iCloud and also the iCloud external domain email accounts set up in Outlook?

I set up four email accounts in Outlook, one for the iCloud email account and one for each of the three external domain email addresses. Then I verified that email. is received by these four email addresses in Outlook. If you get that far, it should work just like mine.

If your iCloud email accounts are not fully set up in Outlook, there is documentation online on how to do this. In a previous post I described the non-trivial process I followed.

Thanks for your response.

I’ve got a couple iCloud aliases and one external domain on iCloud. If I set them up as separate accounts it works indeed but then I get 4 mailboxes with the same emails.

Surely that’s not a solution.

Hi! thank you very much for the tip! that works great. I tried the same on my iphone with outlook. unfortunately that doesn't work. does anyone happen to know what settings I have to take here?