Php, IMAP logout how to?

didn't find any solution in previous questions. I've developed a simple imap access to my server, it's working well, but I've a big problem.

Server is running slow and is getting down due to open imap sessions.

How do I close / logout? In the php imap documentation I don't find a solution, I use this

function correio ($caixa) {
if($caixa ==="Inbox") {
    if($_REQUEST['user'] == "Gmail") {
        $box = imap_open(servidor."INBOX", user, pass) or die (imap_last_error());
        $informacoes = imap_status($box, servidor.$caixa, SA_ALL);
    } else {
        $box = imap_open(servidor, user, pass) or die (imap_last_error());
        $informacoes = imap_status($box, servidor.".".$caixa, SA_ALL);
    }
} else {
    if($_REQUEST['user'] == "Gmail") {
        $box = imap_open(servidor."[Gmail]/".$caixa, user, pass) or die (imap_last_error());
        $informacoes = imap_status($box, servidor."[Gmail]/".$caixa, SA_ALL);
    } else {
        $box = imap_open(servidor.".".$caixa, user, pass) or die (imap_last_error());
        $informacoes = imap_status($box, servidor.".".$caixa, SA_ALL);
    }
}
if($box) {
    $n = imap_check($box);
    $conteudos = imap_fetch_overview($box,"1:{$n->Nmsgs}", 0);
    $msgs .= "<div id='div_".$caixa."' class='menu'>";
        $msgs .= "<h3 id='".$caixa."' class='".$caixa."'>".$caixa."&nbsp;&nbsp;&nbsp;&nbsp;Total: ".$informacoes->messages.", Últimas: ".$informacoes开发者_如何学运维->recent.", Não lidas: ".$informacoes->unseen."</h3>";
        $msgs .= "<div class='mensagens'>";
            if($conteudos) {
                foreach($conteudos as $mensagem) {
                    $de = imap_mime_header_decode($mensagem->from);
                    $msgs .= "<h1 class='".$caixa."'><input type='checkbox' id='".$mensagem->uid."' class='in_".$caixa."' />&nbsp;&nbsp;".$de[0]->text."
                    <script type='text/javascript'>
                        $('input:checkbox').click(function(event) {
                            event.stopPropagation();
                        });
                    </script>   
                    </h1>";
                    $subject = imap_mime_header_decode($mensagem->subject);
                    for ($i=0; $i<count($subject); $i++) {
                        $assunto = $subject[$i]->text;
                    }
                    $msgs .= "<p id='msg_".$mensagem->uid."'>".$assunto."
                                <script type='text/javascript'>
                                    $('#msg_".$mensagem->uid."').click(function() {
                                        ver_mensagem('".$caixa."', '".$mensagem->uid."');
                                    });
                            </script>
                          </p>";
                }
            } else {
                $msgs .= "<h1 class='".$caixa."'>Não há mensagens novas.</h1>";
            }
        $msgs .= "</div>";
    $msgs .= "</div>";
    return $msgs;
    imap_close($box);
} else {
    die("Ligação recusada: " . imap_last_error());
    imap_close($box);
}
}

if($inbox =& correio("Inbox")) {
    $f = $inbox;
    if($spam =& correio("Spam")) {
        $f .= $spam;
    }
}
//echo "f = ".$f."<br />";
$str = "<div id='wrapper'><div id='mobimail' style='display:none'>";
$str .= $f;
$str .= "</div></div>";
$str .= "<div id='footer' class='footer' align='center'>
<div class='todos' align='center'></div>
<div class='apagar' align='center'></div>
<div class='mover' align='center'></div>
<div class='reload' align='center'></div>
<div class='sair' align='center'></div>
</div>";
echo $header."|||".$str;
imap_close($box);
var_dump(imap_close($box));

If the connection is closed, you obviously log out. Closing probably fails, what does imap_close($box) returns?

What is the return value of imap_close()? It can be Either True or False, there is no guarantee that it will always close the stream.

You can try running a simple test setup: imap_open() followed by a simple command such as imap_ping() and then immediate imap_close(). Does this close the connection as expected or does it stay open?

Also make sure you don't call multiple imap_open()s before first closing them. Use either imap_reopen(), call imap_close() before imap_open(), or use a different variable to store the connection identifier (But make sure you imap_close() both of them!).