This code allows you to unhook and remove the default WooCommerce emails.

Add this code to your child theme’s functions.php file or via a plugin that allows custom functions to be added, such as the Dessky Snippets plugin. Please don’t add custom code directly to your parent theme’s functions.php file as this will be overwritten completely when you update the theme.

/**
 * Unhook and remove WooCommerce default emails.
 */
add_action( 'woocommerce_email', 'unhook_those_pesky_emails' );

function unhook_those_pesky_emails( $email_class ) {

		/**
		 * Hooks for sending emails during store events
		 **/
		remove_action( 'woocommerce_low_stock_notification', array( $email_class, 'low_stock' ) );
		remove_action( 'woocommerce_no_stock_notification', array( $email_class, 'no_stock' ) );
		remove_action( 'woocommerce_product_on_backorder_notification', array( $email_class, 'backorder' ) );
		
		// New order emails
		remove_action( 'woocommerce_order_status_pending_to_processing_notification', array( $email_class->emails['WC_Email_New_Order'], 'trigger' ) );
		remove_action( 'woocommerce_order_status_pending_to_completed_notification', array( $email_class->emails['WC_Email_New_Order'], 'trigger' ) );
		remove_action( 'woocommerce_order_status_pending_to_on-hold_notification', array( $email_class->emails['WC_Email_New_Order'], 'trigger' ) );
		remove_action( 'woocommerce_order_status_failed_to_processing_notification', array( $email_class->emails['WC_Email_New_Order'], 'trigger' ) );
		remove_action( 'woocommerce_order_status_failed_to_completed_notification', array( $email_class->emails['WC_Email_New_Order'], 'trigger' ) );
		remove_action( 'woocommerce_order_status_failed_to_on-hold_notification', array( $email_class->emails['WC_Email_New_Order'], 'trigger' ) );
		
		// Processing order emails
		remove_action( 'woocommerce_order_status_pending_to_processing_notification', array( $email_class->emails['WC_Email_Customer_Processing_Order'], 'trigger' ) );
		remove_action( 'woocommerce_order_status_pending_to_on-hold_notification', array( $email_class->emails['WC_Email_Customer_Processing_Order'], 'trigger' ) );
		
		// Completed order emails
		remove_action( 'woocommerce_order_status_completed_notification', array( $email_class->emails['WC_Email_Customer_Completed_Order'], 'trigger' ) );
			
		// Note emails
		remove_action( 'woocommerce_new_customer_note_notification', array( $email_class->emails['WC_Email_Customer_Note'], 'trigger' ) );
}