MAPI Properties

Description: Contains the number of messages in a folder, as computed by the message store.
Property ID: $3602
Property type: PT_LONG
Area: Folder

This property computed by the message store is used for two different, though related, purposes. On a MapiFolder object, it contains the number of messages in a folder. In a heading row in categorized MAPI tables, it contains the number of non-associated messages in the category corresponding to that heading row.
The number contained in this property does not include associated entries in the folder. PR_CONTENT_UNREAD (PidTagContentUnreadCount) contains the count of unread messages for the folder. A client application can read but not change this property and PR_CONTENT_UNREAD.