I have covered this, and how to avoid duplicate names etc., several times in this forum. However the following should work with your code.

Sub ProcessAllMessagesInFolder()'Graham Mayor - https://www.gmayor.com - Last updated - 23 Oct 2019
Dim olItems As Outlook.items
Dim olItem As Object
Dim sPath As String
    Set olItems = Session.PickFolder.items
    For Each olItem In olItems
        If TypeName(olItem) = "MailItem" Then
            saveAttachtoDisk olItem
        End If
        DoEvents
    Next olItem
lbl_Exit:
    Set olItem = Nothing
    Set olItems = Nothing
    Exit Sub
End Sub