通过 Crontab 后台定时发邮件

    $ts = date('Y-m-d h:i:s');
    $sender = mysql_real_escape_string($_POST['user']); 
    $subject = mysql_real_escape_string($_POST['subject']);
    $content = mysql_real_escape_string($_POST["content"]);    
    $query = "
      insert into `mails` set
          `sender` = '$sender',
          `dest` = 'im@helloacm.com',
          `subject` = '$subject',
          `content` = '$content',
          `ts` = '$ts',
          `sent` = 0  
    ";
    // 异步要发的邮件
    $result = mysql_query($query);

  set_time_limit(600);
  $link = mysql_connect("localhost", "user", "password") or die(mysql_error());
                              
  mysql_select_db('database') or die(mysql_error());
  
  mysql_query("SET NAMES 'utf8'");
  mysql_query("SET CHARACTER SET utf8");
  mysql_set_charset("utf-8", $link);
    
  // 获得即将要发送的邮件列表 limit 100 设置每次处理 100封邮件 可以去掉或者改其它数字
  $query = "select * from `mails` where `sent` = 0 limit 100";
  
  $result = mysql_query($query) or die(mysql_error());
  require("PHPMailerAutoload.php");
  $mailer = new PHPMailer();
  $mailer->CharSet = "UTF-8";
  $mailer->IsHTML(true);
  
  // 一封一封的发
  while ($row = mysql_fetch_array($result)) {
    $sender = $row['sender'];
    $dest = $row['dest'];
    $subject = $row['subject'];
    $content = $row['content'];
    $id = $row['id']; 
    $mailer->From = $sender;
    $mailer->FromName = $sender;
    $mailer->ClearAllRecipients();
    $mailer->AddAddress($dest, $dest);
    $mailer->Subject = $subject;
    $mailer->Body = $content;
    if ($mailer->Send()) {
      echo "$sender - OK! <br />";
      // 标记为已经发送
      $query = "update `mails` set `sent` = 1 where `id` = $id";
      mysql_query($query) or die(mysql_error());
    } else {
      echo "$sender - failed! $mailer->ErrorInfo <br />";
    } 
  }

  set_time_limit(600);
  mysql_connect("localhost", "user", "password") or die(mysql_error());
                              
  function run_query($query) {
    echo $query;
    mysql_query($query) or die(mysql_error());
    echo " ***OK!*** \n";
  }         
  
  mysql_select_db('database') or die(mysql_error());  
  $query = 'delete from `mails` where `sent` = 1';  
  run_query($query);