我无法使用Imap连接到Aol帐户

i am trying to connect to Aol accounts using Imap and php 5 (connecting to a specific folder like Inbox or Spam) nut the connection fails

/* the user choose which folder */
$folder = array('Spam' => 'Spam', 'Inbox' => 'Inbox');

$imapInbox = "{imap.aol.com:993/ssl}".$folder[$_POST['folder']];

$imap = imap_open($imapInbox, $email, $pass);

if (!$imap)
{
  echo "<h1>"."Blocked"."</h1>";
  $res .= "<td><b>Blocked</b></td>";
}

if ($imap)
{
  echo "<h1>"."Active"."</h1>";
  $res .= "<td><b>Active</b></td>";
} 

this is the output "Blocked " although that the eamil works just fine