Get Emails related to a given Account, REST

rest.php

<?php

    $method = 'login';
    $parameters = array('user_auth' => array('user_name' => 'admin', 'password' => md5('admin')));
    $response = makeRESTCall($method, $parameters);
    $session = $response['id'];

    $method = 'get_relationships';
    $relationship = 'email_addresses';
    $module = 'Accounts';
    $id = '5f7ff434-eb56-b3b5-81cf-51069cf53a04';
    $relatedFields = array('id', 'email_address', 'invalid_email', 'opt_out');
    $parameters = array($session, $module, $id, $relationship, '', $relatedFields, array(), false);
    $response = makeRESTCall($method, $parameters);
    print_r($response);

    function makeRESTCall($method, $parameters)
    {
        // specify the REST web service to interact with
	$url = 'http://127.0.0.1/Mango/ent/sugarcrm/service/v4/rest.php';
        // Open a curl session for making the call
        $curl = curl_init($url);
        // set URL and other appropriate options
        curl_setopt($curl, CURLOPT_URL, $url);
        curl_setopt($curl, CURLOPT_POST, 1);
        curl_setopt($curl, CURLOPT_HEADER, 0);
        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, 0);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($curl, CURLOPT_FOLLOWLOCATION, 0);
        curl_setopt($curl, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_0 );
        // build the request URL
        $json = json_encode($parameters);
        $postArgs = "method=$method&input_type=JSON&response_type=JSON&rest_data=$json";
        curl_setopt($curl, CURLOPT_POSTFIELDS, $postArgs);
        // Make the REST call, returning the result
        $response = curl_exec($curl);
        // Close the connection
        curl_close($curl);

        // Convert the result from JSON format to a PHP array
        return json_decode($response,true);
    }

?>