WooCommerce order email billing country

functions.php

/*
 * Let's add some more information to the customer details block in admin emails
 * This particular example adds the billing country
 */
function mysite_filter_woocommerce_email_customer_details_fields( $fields, $sent_to_admin, $order ) {

    if ( $order->billing_country ) {
        $fields['billing_country'] = array(
            'label' => __( 'Country', 'woocommerce' ),
            'value' => WC()->countries->countries[ $order->billing_country ],
        );
    }

    return $fields;
};

// add the filter
add_filter( 'woocommerce_email_customer_details_fields', 'mysite_filter_woocommerce_email_customer_details_fields', 10, 3 );