Estado personalizado para woo con envío de mail

functions.php

<?php // register a custom post status 'payment-confirmed' for Orders
add_action( 'init', 'register_custom_post_status', 20 );
function register_custom_post_status() {
    register_post_status( 'wc-payment-confirmed', array(
        'label'                     => _x( 'Pago confirmado', 'Order status', 'woocommerce' ),
        'public'                    => true,
        'exclude_from_search'       => false,
        'show_in_admin_all_list'    => true,
        'show_in_admin_status_list' => true,
        'label_count'               => _n_noop( 'Pago confirmado <span class="count">(%s)</span>', 'Pago confirmado <span class="count">(%s)</span>', 'woocommerce' )
    ) );

    if (function_exists('acf_add_options_page')) {
        $parent = acf_add_options_page(array(
            'page_title' 	=> 'Configuración',
            'menu_title'	=> 'Configuración',
            'menu_slug' 	=> 'configuracion',
            'redirect'		=> false
        ));
    }
}

// Adding custom status 'payment-confirmed' to order edit pages dropdown
add_filter( 'wc_order_statuses', 'custom_wc_order_statuses', 20, 1 );
function custom_wc_order_statuses( $order_statuses ) {
    $order_statuses['wc-payment-confirmed'] = _x( 'Pago confirmado', 'Order status', 'woocommerce' );
    return $order_statuses;
}

// Adding custom status 'payment-confirmed' to admin order list bulk dropdown
add_filter( 'bulk_actions-edit-shop_order', 'custom_dropdown_bulk_actions_shop_order', 20, 1 );
function custom_dropdown_bulk_actions_shop_order( $actions ) {
    $actions['mark_payment-confirmed'] = __( 'Mark Pago confirmado', 'woocommerce' );
    return $actions;
}

// Adding action for 'payment-confirmed'
add_filter( 'woocommerce_email_actions', 'custom_email_actions', 20, 1 );
function custom_email_actions( $action ) {
    $actions[] = 'woocommerce_order_status_wc-payment-confirmed';
    return $actions;
}

if ( class_exists( 'WooCommerce' ) ) {
    add_action( 'woocommerce_order_status_wc-payment-confirmed', array( WC(), 'send_transactional_email' ), 10, 1 );
}

// Sending an email notification when order get 'payment-confirmed' status
add_action('woocommerce_order_status_payment-confirmed', 'backorder_status_custom_notification', 20, 2);
function backorder_status_custom_notification( $order_id, $order ) {
    // HERE below your settings
    $heading   = __('Tu orden - Pago confirmado','woocommerce');
    $subject   = 'Hemos confirmado tu pago - {order_number}';

    // Getting all WC_emails objects
    $mailer = WC()->mailer()->get_emails();

    // Customizing Heading and subject In the WC_email processing Order object
    $mailer['WC_Email_Customer_Processing_Order']->heading = $heading;
    $mailer['WC_Email_Customer_Processing_Order']->subject = $subject;

    // Sending the customized email
    $mailer['WC_Email_Customer_Processing_Order']->trigger( $order_id );
}