Code-Snippets-Functions/Execute a function on a child site/WooCommerce/disable-order-completed-email-when-order-items-have-specific-product.txt

add_filter( 'woocommerce_email_recipient_customer_completed_order', 'product_tag_avoid_completed_email_notification', 10, 2 );
function product_tag_avoid_completed_email_notification( $recipient, $order ) {
    if ( is_a( $order, 'WC_Order' ) ) {
        // HERE set your product tags (comma-separated term names, slugs or Ids)
        $targeted_terms    = array('special-promo', 'regular');
        $targeted_taxonomy = 'product_tag';

        // Loop through order items
        foreach ( $order->get_items() as $item ) {
            // Check for matching product tags 
            if ( has_term( $targeted_terms, $targeted_taxonomy, $item->get_product_id() ) ) {
                return ''; // return empty recipient avoiding this email notification
            }
        }
    }
    return $recipient;
}