Use the following macro to call the process

Sub ProcessSelection()
Dim olMailItem As Object
    'An Outlook macro by Graham Mayor
    If Application.ActiveExplorer.Selection.Count = 0 Then
        MsgBox "No Items selected!", vbCritical, "Error"
        Exit Sub
    End If
    On Error Resume Next
    For Each olMailItem In Application.ActiveExplorer.Selection
        If TypeName(olMailItem) = "MailItem" Then
            SaveAttachments olMailItem
        End If
        DoEvents
    Next olMailItem
Err_Handler:
    Set olMailItem = Nothing
lbl_Exit:
    Exit Sub
End Sub