DocumentItem Object
A DocumentItem object is any document other than a Microsoft Outlook item as an item in an Outlook folder. In common usage, this will be an Office document but may be any type of document or executable file.
Note When you try to programmatically add a user-defined property to a DocumentItem object, you receive the following error message: "Property is read-only." This is because the Outlook object model does not support this functionality.
Example
The following Visual Basic for Applications (VBA) example shows how to create a DocumentItem.
Sub AddDocItem()
Dim outApp As New Outlook.Application
Dim nsp As Outlook.NameSpace
Dim mpfInbox As Outlook.MAPIFolder
Dim doci As Outlook.DocumentItem
Set nsp = outApp.GetNamespace("MAPI")
Set mpfInbox = nsp.GetDefaultFolder(olFolderInbox)
Set doci = mpfInbox.Items.Add(olWordDocumentItem)
doci.Subject = "Word Document Item"
doci.Save
End Sub