Hi, Is the EntryID property for an Outlook Folder guaranteed to be unique across multiple mail stores? My Outlook add in currently persists the only the EntryID of a folder selected by the user (typically in his default mail store, but theoretically could be from any of the stores available to the user) so as to be able to reference that folder. So when I need a reference to this folder, I use Namespace.GetFolderFromID(mySpecialFoldersEntryID), without specifying a StoreID. Is this guaranteed to work even if the user subsequently decides to configure multiple stores of any type? Or will I need to persist the StoreID of the folder as well?