Change email recipients

change_recipient_for_expired_sub_notification.php

<?php
add_filter( 'woocommerce_email_recipient_expired_subscription', 'wcs_change_recipient_for_expired_sub_notification', 10, 2 );
 
function wcs_change_recipient_for_expired_sub_notification( $recipient, $order ) {
    $page = $_GET['page'] = isset( $_GET['page'] ) ? $_GET['page'] : '';
    if ( 'wc-settings' === $page ) {
      return $recipient; 
    }
    $recipient = $order->billing_email;
    return $recipient;
}

wcs_disable_customer_order_email_if_free.php

<?php
add_filter( 'woocommerce_email_recipient_customer_processing_renewal_order', 'wcs_disable_customer_order_email_if_free', 10, 2 );
add_filter( 'woocommerce_email_recipient_customer_completed_renewal_order', 'wcs_disable_customer_order_email_if_free', 10, 2 );
  
// If Total = 0 we change the email recipient to ""
 
function wcs_disable_customer_order_email_if_free( $recipient, $order ) {
    $page = $_GET['page'] = isset( $_GET['page'] ) ? $_GET['page'] : '';
    if ( 'wc-settings' === $page ) {
      return $recipient; 
    }
    if( $order->get_total() === '0.00' ) $recipient = '';
    return $recipient;
}

Thanks a lot for the code, it worked like a charm.

I just have one question about the code, what does this line of code does?
$page = $_GET['page'] = isset( $_GET['page'] ) ? $_GET['page'] : '';

I just have one question about the code, what does this line of code does? $page = $_GET['page'] = isset( $_GET['page'] ) ? $_GET['page'] : '';

That checks if you're in wp-admin and looking at the wc-settings page. If that's the case, then it doesn't change the recipient email. It will only change the recipient email in other contexts, such as during the sending of the email itself.

Thanks a lot for your code and guidance. I really appreciate it!