A folder object is a MAPI object that provides access to a folder in an information store. You use a folder object to manipulate messages within a folder. You create folder objects with the MAPI calls IMsgStore::OpenEntry (for an existing folder) and IMAPIFolder::CreateFolder (for a new folder), and you release folder objects with a call to IUnknown::Release.
Because folders reside in Microsoft Exchange Server information stores, this section describes the way the Microsoft Exchange Server information store provider implements folder objects.
For more information on accessing folder objects through MAPI, see Working with Folders.
After a call to CreateFolder or OpenEntry, the entry identifier of the open folder is stored on the client. (You used the entry identifier of the folder to open it.) Because it is stored locally, getting this property does not cause an RPC.
Note This section describes the implementation of properties by the Microsoft Exchange Server information store provider, not the service provider that controls access to a user’s set of personal folders (which are stored in a file that usually has the extension .PST.)