SwiftMailer库执行缓慢

batchsend()

$query = \"SELECT * FROM `smtp`\";
    $result = mysql_query($query) or die(mysql_error());
    $num_rows1 = mysql_num_rows($result);
    while($row = mysql_fetch_array($result)){
        $smtp = $row[\'ip\'];
        $login = $row[\'user\'];
        $pass = $row[\'pass\'];
        $smtp_domain = $row[\'domain\'];   

    $querya = \"SELECT * FROM `mailer_lists` ml JOIN `mailer_controller` mc ON ml.project_name = mc.project_name LIMIT \".$global_limit.\"\";
    $resulta = mysql_query($querya) or die(mysql_error());
    $num_rows2 = mysql_num_rows($resulta);

    // quickly check if any mail returned query
    if ($num_rows2 < 1){
        mysql_close($connection);
        echo \"Nothing to mail... \\n\";
        die();
        }

    while($rowa = mysql_fetch_array($resulta)){
        $email[] = $rowa[\'email\'];
        $project_name = $rowa[\'project_name\'];
        $from_name = $rowa[\'from_name\'];
        $subject = $rowa[\'subject\'];
        $body = $rowa[\'body\'];
        $from = array($spun_from_email => $spun_from_name);
    }    

    require_once \'swift/swift_required.php\';
        $transport = Swift_SmtpTransport::newInstance(\'\'.$smtp.\'\', 25)
          ->setUsername($login)
          ->setPassword($pass)
          ;
        $mailer = Swift_Mailer::newInstance($transport);
        $message = Swift_Message::newInstance()
          ->setSubject($subject)
          ->setFrom($from)
         // ->addPart(\'add part message\', \'text/html\')
         // ->attach(Swift_Attachment::fromPath(\'\'))
          ->setTo($email)
          ->setBody($body)
        ;
        $mailout = $mailer->batchSend($message);
         // ->addPart(\'add part message\', \'text/html\')
         // ->attach(Swift_Attachment::fromPath(\'\'))
          ;  


            $queryb = \"DELETE FROM `mailer_lists` WHERE `project_name` = \'\".$project_name.\"\' AND `email` = \'\".implode(\'\\\' OR `email` = \\\'\',$email).\"\'\";  
            $resultb = mysql_query($queryb) or die(mysql_error());
            $c++;
            echo \"sent $num_rows1 emails to smtp $c \\n\";
        }