private void ShowStoreInTree(IMsgStore store) { //Add the stuff in this store to the tree MapiStoreNode storeNode = new MapiStoreNode(store); treeFolders.Nodes.Add(storeNode); //Get the ID of the root folder ENTRYID rootIpmFolder = MapiUtils.GetEntryIdProperty(store, Tags.PR_IPM_SUBTREE_ENTRYID); MAPI33.MAPI.TYPE objType; IUnknown unk; Error hr = store.OpenEntry(rootIpmFolder, Guid.Empty, 0, out objType, out unk); if (hr != Error.Success) { throw new MapiException(hr); } using (unk) { IMAPIFolder folder = (IMAPIFolder)unk; using (folder) { ShowFolderInTree(storeNode, folder); } } }