You can share calendar information in Microsoft Outlook by either sharing a calendar folder, if you have an Exchange Server account, or by exporting the contents of a calendar folder to an iCalendar calendar (.ics) file. Calendar information can also be shared online using a variety of protocols. For more information about sharing online calendars, see Sharing Online Calendars, RSS Feeds, Microsoft SharePoint Foundation Folders, and Exchange Folders.
Sharing messages are used to either invite or request access to a calendar folder, or to respond to a sharing invitation or request by either allowing or denying access to a calendar folder. To construct a sharing invitation or sharing request, the CreateSharingItem method of the NameSpace object is used to create a SharingItem object. A Folder object reference to the desired calendar folder is used to establish the sharing context for the sharing message.
You can only reference the Calendar default folder when creating a sharing request. A single SharingItem object can represent both a sharing invitation and a sharing request, if the Calendar default folder is used as the sharing context.
Sharing responses are automatically created and sent by calling the Allow or Deny methods of a SharingItem which represents a sharing request. Calling the Allow or Deny method allows or denies, respectively, access to the requested folder - the user requesting access need not receive the sharing response.
The CalendarSharing object is used to export information from the calendar folder to an iCalendar calendar file, and can also be used to create a MailItem object that not only contains the iCalendar calendar file as an attachment, but also provides the calendar information as formatted HTML within the body of the mail message. The CalendarSharing object provides several properties that can be used to limit the scope and detail of calendar information included in the iCalendar calendar file and in the body of the MailItem.
The GetCalendarExporter method of the Folder object is used to obtain a CalendarSharing object reference for a specified calendar folder. From the CalendarSharing object, you can either use the SaveAsICal method to save an iCalendar calendar file, or you can use the ForwardAsICal method to create a MailItem that contains both formatted calendar information and an iCalendar calendar file.
Once exported, an iCalendar calendar file can be opened by using the OpenSharedFolder method of the NameSpace object.