ECSHOP发送邮件的代码 如何优化？请高手指点~我使用的PHPMailer,

$email_list = get_order_email_list($ids); //取得要发送邮件的ID列表 ini_set;
$tpl = get_mail_template('deliver_notice');//取出邮件模板
foreach($email_list['emaildb'] AS $key => $row) //开始发邮件
{
$order = order_info($row['order_id']);//订单信息
$order['invoice_no'] = $row['invoice_no'];//赋值
$GLOBALS['smarty']->assign('order', $order);
$GLOBALS['smarty']->assign('send_time', date("Y-m-d h:i:s",gmtime()));
$GLOBALS['smarty']->assign('shop_name', $GLOBALS['_CFG']['shop_name']);
$GLOBALS['smarty']->assign('send_date', local_date($GLOBALS['_CFG']['date_format']));
$GLOBALS['smarty']->assign('sent_date', local_date($GLOBALS['_CFG']['date_format']));
$GLOBALS['smarty']->assign('confirm_url', $GLOBALS['ecs']->url() . 'receive.php?id=' . $order['order_id'] .
 '&con=' . rawurlencode($order['consignee']));
$GLOBALS['smarty']->assign('send_msg_url',$GLOBALS['ecs']->url() . 'user.php?act=message_list&order_id=' . $order['order_id']);
$content = $GLOBALS['smarty']->fetch('str:' . $tpl['template_content']);
send_mail_weiyuanliu($order['email'],$order['consignee'],$tpl['template_subject'].'-'.$order['consignee'].'-'.$row['invoice_no'],$content);//发送邮件
$GLOBALS['db']->query("UPDATE ". $ecs->table('mail_list') ." SET is_send = 1 WHERE id = ". $row['id'] ." ");//更新发送状态
}
ecs_header("Location: order.php?act=order_mail_list");
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一次只能发几封邮件，应该如何优化一下呢？多了就白屏了~ 高手们啊,小弟伤不起了,有木有好心人啊!!!