Private Sub RemoveRecipients(Item As Outlook.MailItem)
  Dim RemoveThis As VBA.Collection
  Dim Recipients As Outlook.Recipients
  Dim R As Outlook.Recipient
  Dim i&, y&
  Set RemoveThis = New VBA.Collection

  ' here add addresses
  RemoveThis.Add "abc@domain.de"
  RemoveThis.Add "test@domain.com"

  Set Recipients = Item.Recipients
  For i = Recipients.Count To 1 Step -1
    Set R = Recipients.Item(i)

    For y = 1 To RemoveThis.Count
      If LCase$(R.Address) = LCase$(RemoveThis(y)) Then
        Recipients.Remove i
        Exit For
      End If
    Next
  Next
End Sub

Private Sub Application_ItemSend(ByVal Item As Object, Cancel As Boolean)
  On Error Resume Next
  RemoveRecipients Item
End Sub