public static function init_transactional_emails() {
		$email_actions = apply_filters(
			'woocommerce_email_actions',
			array(
				'woocommerce_low_stock',
				'woocommerce_no_stock',
				'woocommerce_product_on_backorder',
				'woocommerce_order_status_pending_to_processing',
				'woocommerce_order_status_pending_to_completed',
				'woocommerce_order_status_processing_to_cancelled',
				'woocommerce_order_status_pending_to_failed',
				'woocommerce_order_status_pending_to_on-hold',
				'woocommerce_order_status_failed_to_processing',
				'woocommerce_order_status_failed_to_completed',
				'woocommerce_order_status_failed_to_on-hold',
				'woocommerce_order_status_cancelled_to_processing',
				'woocommerce_order_status_cancelled_to_completed',
				'woocommerce_order_status_cancelled_to_on-hold',
				'woocommerce_order_status_on-hold_to_processing',
				'woocommerce_order_status_on-hold_to_cancelled',
				'woocommerce_order_status_on-hold_to_failed',
				'woocommerce_order_status_completed',
				'woocommerce_order_fully_refunded',
				'woocommerce_order_partially_refunded',
				'woocommerce_new_customer_note',
				'woocommerce_created_customer',
			)
		);

		if ( apply_filters( 'woocommerce_defer_transactional_emails', false ) ) {
			self::$background_emailer = new WC_Background_Emailer();

			foreach ( $email_actions as $action ) {
				add_action( $action, array( __CLASS__, 'queue_transactional_email' ), 10, 10 );
			}
		} else {
			foreach ( $email_actions as $action ) {
				add_action( $action, array( __CLASS__, 'send_transactional_email' ), 10, 10 );
			}
		}
	}