title: Google calendar API- Invitation email doesn't send to attendees when create event
body: <p>I want to add event to google calendar using google api.
  But after event created, invitation email doesn't send to attendees email list.
  Here is my code: </p>
  
  <pre><code> &lt;?php
      require_once '../../src/Google_Client.php';
      require_once '../../src/contrib/Google_CalendarService.php';
      session_start();
  
      $client = new Google_Client();
      $client-&gt;setApplicationName("Google Calendar PHP Starter Application");
  
      // Visit https://code.google.com/apis/console?api=calendar to generate your
      // client id, client secret, and to register your redirect uri.
       $client-&gt;setClientId('309388785502.apps.googleusercontent.com');
       $client-&gt;setClientSecret('hvJQUDYz4rY0HiYcgS46yxB-');
       $client-&gt;setRedirectUri('http://localhost/GoogleApi/google-api-php-client/examples/calendar/simple.php');
       $client-&gt;setDeveloperKey('AIzaSyAbBRxRKM9mkXKA17Bruul6lCq-vhR6gqc');
      $cal = new Google_CalendarService($client);
      if (isset($_GET['logout'])) {
        unset($_SESSION['token']);
      }
  
      if (isset($_GET['code'])) {
        $client-&gt;authenticate($_GET['code']);
        $_SESSION['token'] = $client-&gt;getAccessToken();
        header('Location: http://' . $_SERVER['HTTP_HOST'] . $_SERVER['PHP_SELF']);
      }
  
      if (isset($_SESSION['token'])) {
        $client-&gt;setAccessToken($_SESSION['token']);
      }
  
      if ($client-&gt;getAccessToken()) {
  
       $event = new Google_Event();
        $event-&gt;setSummary('Halloween3');
        $event-&gt;setLocation('The Neighbourhood');
        $start = new Google_EventDateTime();
        $start-&gt;setDate('2013-10-3');
        $event-&gt;setStart($start);
        $end = new Google_EventDateTime();
        $end-&gt;setDate('2013-10-3');
        $event-&gt;setEnd($end);
        $event-&gt;sendNotifications=true;
        $event-&gt;maxAttendees=2;
        $attendee1 = new Google_EventAttendee();
        $attendee2 = new Google_EventAttendee();
      $attendee1-&gt;setEmail("cuong***.ictu@gmail.com");
      $attendee2-&gt;setEmail("webtr***@gmail.com");
      $attendees = array($attendee1,$attendee2);
      $event-&gt;attendees = $attendees;
  
        $createdEvent = $cal-&gt;events-&gt;insert('primary', $event);
  
      $_SESSION['token'] = $client-&gt;getAccessToken();
      } else {
        $authUrl = $client-&gt;createAuthUrl();
        print "&lt;a class='login' href='$authUrl'&gt;Connect Me!&lt;/a&gt;";
      }
  
  ?&gt;
  </code></pre>
  
  <p>So my question is how can i send email to attendees list after event created from API?
  Thank you.</p>