php Socket發送郵件驗證郵箱的真實有效性而非格式

<?php

/請尊重別人的勞動成功，請保留此版權信息，謝謝！
作者：小露珠3.3
揚帆修正一點東西：在代碼中已經用注釋注明，本代碼現在向qq發信沒問題～/
set_time_limit(120);
class smtp_mail
{
    var $host;           //主機
    var $port;           //端口 一般為25
    var $user;           //SMTP認證的帳號
    var $pass;           //認證密碼
    var $debug = false;   //是否顯示和服務器會話信息？
    var $conn;
    var $result_str;       //結果
    var $in;           //客戶機發送的命令
    var $from;           //源信箱
    var $to;           //目標信箱
    var $subject;         //主題
    var $body;           //內容
    function smtp_mail($host,$port,$user,$pass,$debug=false)
    {
       $this->host   = $host;
       $this->port   = $port;
       $this->user   = base64_encode($user);
       $this->pass   = base64_encode($pass);
       $this->debug   = $debug;
       $this->socket = socket_create (AF_INET, SOCK_STREAM, SOL_TCP);   //具體用法請參考手冊
       if($this->socket)
       {
       $this->result_str   =   "創建SOCKET:".socket_strerror(socket_last_error());
       $this->debug_show($this->result_str);
       }
       else
       {
       exit("初始化失敗，請檢查您的網絡連接和參數");
       }
       $this->conn = socket_connect($this->socket,$this->host,$this->port);
       if($this->conn)
       {
       $this->result_str   =   "創建SOCKET連接:".socket_strerror(socket_last_error());
       $this->debug_show($this->result_str);
       }
       else
       {
       exit("初始化失敗，請檢查您的網絡連接和參數");
       }
       $this->result_str = "服務器應答：<font color=#cc0000>".socket_read ($this->socket, 1024)."</font>";
       $this->debug_show($this->result_str);

}
function debug_show($str)
{
   if($this->debug)
   {
   echo $str."<p>\r\n";
   }
}
function send($from,$to,$subject,$body)
{
   if($from == "" || $to == "")
   {
   exit("請輸入信箱地址");
   }
   if($subject == "") $sebject = "無標題";
   if($body     == "") $body     = "無內容";
   $this->from     =   $from;
   $this->to       =   $to;
   $this->subject   =   $subject;
   $this->body     =   $body;

       //揚帆修改部分代碼
   $All           = "From:<".$this->from.">\r\n";
   $All           .= "To:<".$this->to.">\r\n";
   $All           .= "Subject:".$this->subject."\r\n\r\n";
   $All           .= $this->body;
   /*
   如過把$All的內容再加處理，就可以實現發送MIME郵件了
   不過還需要加很多程序
   */

   //以下是和服務器會話
   $this->in       =   "EHLO HELO\r\n";
   $this->docommand();

   $this->in       =   "AUTH LOGIN\r\n";
   $this->docommand();

   $this->in       =   $this->user."\r\n";
   $this->docommand();

   $this->in       =   $this->pass."\r\n";
   $this->docommand();

// $this->in       =   "MAIL FROM:".$this->from."\r\n";
   $this->in       =   "MAIL FROM:<".$this->from.">\r\n";   //揚帆修改
   $this->docommand();

// $this->in       =   "RCPT TO:".$this->to."\r\n";
   $this->in       =   "RCPT TO:<".$this->to.">\r\n";     //揚帆修改
   $this->docommand();

   $this->in       =   "DATA\r\n";
   $this->docommand();

     $this->in       =   $All."\r\n.\r\n";
   $this->docommand();

   $this->in       =   "QUIT\r\n";
   $this->docommand();

   //結束，關閉連接

}
function docommand()
{
   socket_write ($this->socket, $this->in, strlen ($this->in));
   $this->debug_show("客戶機命令：".$this->in);
   $this->result_str = "服務器應答：<font color=#cc0000>".socket_read ($this->socket, 1024)."</font>";
   $this->debug_show($this->result_str);
}

}
?></pre> 


 php代碼 

<?php
//測試頁面
include "smtp_mail.php";

//你用這個類的時候你修改成你自己的信箱就可以了
$smtp=new smtp_mail("smtp.qq.com","25","yourmail@qq.com","Your password",true);
//如果你需要顯示會話信息，請將上面的修改成
//$smtp   =   new smtp_mail("smtp.qq.com","25","你的qq.com的帳號","你的密碼",true);
$smtp->send("yourmail@qq.com","yourmail@qq.com","你好","測試郵件");
?> </pre>