When printing pack lists mark as printed (similiar to printing cust invoices) so cant be printed twice, can get confusing receiving email and going to sales order screen to print and new order drops in meantime. Just need a new status of printed in between ready and awaiting packing or put the little printer icon on that screen after printed, or, as per other suggestion, make all orders auto print so dont need the emails or no need to go the release screen at all then.