php通过smtp发送邮件

<?php
/***************************************
** Filename.......: class.smtp.inc
** Project........: SMTP Class
** Version........: 1.00b
** Last Modified..: 30 September 2001
***************************************/

 define('SMTP_STATUS_NOT_CONNECTED', 1, TRUE);
 define('SMTP_STATUS_CONNECTED', 2, TRUE);

 class smtp{

  var $connection;
  var $recipients;
  var $headers;
  var $timeout;
  var $errors;
  var $status;
  var $body;
  var $from;
  var $host;
  var $port;
  var $helo;
  var $auth;
  var $user;
  var $pass;

  /***************************************
        ** Constructor function. Arguments:
  ** $params - An assoc array of parameters:
  **
  **   host    - The hostname of the smtp server  Default: localhost
  **   port    - The port the smtp server runs on  Default: 25
  **   helo    - What to send as the HELO command  Default: localhost
  **             (typically the hostname of the
  **             machine this script runs on)
  **   auth    - Whether to use basic authentication Default: FALSE
  **   user    - Username for authentication   Default: <blank>
  **   pass    - Password for authentication   Default: <blank>
  **   timeout - The timeout in seconds for the call Default: 5
  **             to fsockopen()
        ***************************************/

  function smtp($params = array()){

   if(!defined('CRLF'))
    define('CRLF', "\r\n", TRUE);
   
   $this->timeout = 5;
   $this->status = SMTP_STATUS_NOT_CONNECTED;
   $this->host  = 'localhost';
   $this->port  = 25;
   $this->helo  = 'localhost';
   $this->auth  = FALSE;
   $this->user  = '';
   $this->pass  = '';
   $this->errors   = array();

   foreach($params as $key => $value){
    $this->$key = $value;
   }
  }

  /***************************************
        ** Connect function. This will, when called
  ** statically, create a new smtp object,
  ** call the connect function (ie this function)
  ** and return it. When not called statically,
  ** it will connect to the server and send
  ** the HELO command.
        ***************************************/

  function connect($params = array()){

   if(!isset($this->status)){
    $obj = new smtp($params);
    if($obj->connect()){
     $obj->status = SMTP_STATUS_CONNECTED;
    }

    return $obj;

   }else{
    $this->connection = fsockopen($this->host, $this->port, $errno, $errstr, $this->timeout);
    socket_set_timeout($this->connection, 0, 250000);

    $greeting = $this->get_data();
    if(is_resource($this->connection)){
     return $this->auth ? $this->ehlo() : $this->helo();
    }else{
     $this->errors[] = 'Failed to connect to server: '.$errstr;
     return FALSE;
    }
   }
  }

  /***************************************
        ** Function which handles sending the mail.
  ** Arguments:
  ** $params - Optional assoc array of parameters.
  **            Can contain:
  **              recipients - Indexed array of recipients
  **              from       - The from address. (used in MAIL FROM:),
  **                           this will be the return path
  **              headers    - Indexed array of headers, one header per array entry
  **              body       - The body of the email
  **            It can also contain any of the parameters from the connect()
  **            function
        ***************************************/

  function send($params = array()){

   foreach($params as $key => $value){
    $this->set($key, $value);
   }

   if($this->is_connected()){

    // Do we auth or not? Note the distinction between the auth variable and auth() function
    if($this->auth){
     if(!$this->auth())
      return FALSE;
    }

    $this->mail($this->from);
    if(is_array($this->recipients))
     foreach($this->recipients as $value)
      $this->rcpt($value);
    else
     $this->rcpt($this->recipients);

    if(!$this->data())
     return FALSE;

    // Transparency
    $headers = str_replace(CRLF.'.', CRLF.'..', trim(implode(CRLF, $this->headers)));
    $body    = str_replace(CRLF.'.', CRLF.'..', $this->body);
    $body    = $body[0] == '.' ? '.'.$body : $body;

    $this->send_data($headers);
    $this->send_data('');
    $this->send_data($body);
    $this->send_data('.');

    return (substr(trim($this->get_data()), 0, 3) === '250');
   }else{
    $this->errors[] = 'Not connected!';
    return FALSE;
   }
  }
  
  /***************************************
        ** Function to implement HELO cmd
        ***************************************/

  function helo(){
   if(is_resource($this->connection)
     AND $this->send_data('HELO '.$this->helo)
     AND substr(trim($error = $this->get_data()), 0, 3) === '250' ){

    return TRUE;

   }else{
    $this->errors[] = 'HELO command failed, output: ' . trim(substr(trim($error),3));
    return FALSE;
   }
  }
  
  /***************************************
        ** Function to implement EHLO cmd
        ***************************************/

  function ehlo(){
   if(is_resource($this->connection)
     AND $this->send_data('EHLO '.$this->helo)
     AND substr(trim($error = $this->get_data()), 0, 3) === '250' ){

    return TRUE;

   }else{
    $this->errors[] = 'EHLO command failed, output: ' . trim(substr(trim($error),3));
    return FALSE;
   }
  }
  
  /***************************************
        ** Function to implement AUTH cmd
        ***************************************/

  function auth(){
   if(is_resource($this->connection)
     AND $this->send_data('AUTH LOGIN')
     AND substr(trim($error = $this->get_data()), 0, 3) === '334'
     AND $this->send_data(base64_encode($this->user))   // Send username
     AND substr(trim($error = $this->get_data()),0,3) === '334'
     AND $this->send_data(base64_encode($this->pass))   // Send password
     AND substr(trim($error = $this->get_data()),0,3) === '235' ){

    return TRUE;

   }else{
    $this->errors[] = 'AUTH command failed: ' . trim(substr(trim($error),3));
    return FALSE;
   }
  }

  /************************