The E-mail all selected purchase orders check box is used to generate and send previously unsent Open PO(s) and Approved PO Mods to the vendors. When this is checked, Approved and Open statuses are checked in Purchase Order Status, the E-mail check box in Default Delivery Method is checked, and  the Include purchase orders that were not printed or E-mailed check box is checked in Actual Delivery Method . The E-mail all selected purchase orders check box and Print all selected purchase orders check box are mutually exclusive.