How do I change the From address to my custom domain in Outlook? It works correctly when I send messages in the browser.

How to Fix:

1. Use iCloud to set up Outlook
2. Right-click on your iCloud.com email address, Account Properties
3. Click Account Settings > Manage Profiles
4. Click Email Accounts
5. Select your @icloud.com email address, click Change
6. Change your email address to the custom one that you're registered at iCloud.com
7. Click Next. Outlook will test the new settings and send you a test email.
8. Click Finish.

Your emails will now send with your custom email address instead of your iCloud.com email address.