If you've set up an account using iCloud System Preferences or macOS Mail in 10.7.4 or later, you won't see these settings because they're automatically configured. ICloud Mail uses the IMAP and SMTP standards that are supported by most modern email client apps. Use iCloud settings on your iPhone, iPad or iPod touch with iOS 7 or later. Set up two-factor authentication and generate an app-specific password to use for iCloud Mail. Use iCloud for Windows on your PC in Microsoft Windows with Outlook 2010 to Outlook 2016.
Use iCloud Preferences on your Mac in OS X Lion 10.7.4 or later. You won't need these email server settings if you meet iCloud system requirements and can use any of these setup methods: You will need these server settings to hand when you manually configure your email client app. With these iCloud Mail server settings, you can set up your email client app to send and receive email with your iCloud Mail account. Use these iCloud Mail server settings to manually set up your iCloud Mail account in an email client app. ICloud Mail server settings for other email client apps
