Wissensdatenbank

If you're hosting email on a custom domain name and that domain is set up to use shared calendaring, you may be able to control who can and cannot view your calendar. The sharing of email calendars is determined by your email administrator.
    
    When your calendar is shared with other users, they are able to view your calendar and event details. Users cannot edit or add events to your calendar.
    
    You may want to make certain events private (e.g., doctor appointments). To make an event private, or, to make all existing events private or public, see the "Making All Events Private or Public" help article.
    
    1. To control who can and cannot view your personal calendar, click the arrow on the Calendar tab, and then select Calendar Manager.
    2. In the Personal Calendars box, click the Sharing link for your personal calendar.
    3. Indicate whether you want to share your calendar with no one, with all users in your domain, or with only specific users.
    4. If you want to share your calendar only with specific users, select from the list of users in your domain. Or, enter an email address manually and click the Add button.
    5. Click the Save button.