class.smtp.php

<?php
/*~ class.smtp.php
.---------------------------------------------------------------------------.
|  Software: PHPMailer - PHP email class                                    |
|   Version: 5.2.1                                                          |
|      Site: https://code.google.com/a/apache-extras.org/p/phpmailer/       |
| ------------------------------------------------------------------------- |
|     Admin: Jim Jagielski (project admininistrator)                        |
|   Authors: Andy Prevost (codeworxtech) codeworxtech@users.sourceforge.net |
|          : Marcus Bointon (coolbru) coolbru@users.sourceforge.net         |
|          : Jim Jagielski (jimjag) jimjag@gmail.com                        |
|   Founder: Brent R. Matzelle (original founder)                           |
| Copyright (c) 2010-2012, Jim Jagielski. All Rights Reserved.              |
| Copyright (c) 2004-2009, Andy Prevost. All Rights Reserved.               |
| Copyright (c) 2001-2003, Brent R. Matzelle                                |
| ------------------------------------------------------------------------- |
|   License: Distributed under the Lesser General Public License (LGPL)     |
|            http://www.gnu.org/copyleft/lesser.html                        |
| This program is distributed in the hope that it will be useful - WITHOUT  |
| ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or     |
| FITNESS FOR A PARTICULAR PURPOSE.                                         |
'---------------------------------------------------------------------------'
*/

/**
 * PHPMailer - PHP SMTP email transport class
 * NOTE: Designed for use with PHP version 5 and up
 * @package PHPMailer
 * @author Andy Prevost
 * @author Marcus Bointon
 * @copyright 2004 - 2008 Andy Prevost
 * @author Jim Jagielski
 * @copyright 2010 - 2012 Jim Jagielski
 * @license http://www.gnu.org/copyleft/lesser.html Distributed under the Lesser General Public License (LGPL)
 * @version $Id: class.smtp.php 450 2010-06-23 16:46:33Z coolbru $
 */

/**
 * SMTP is rfc 821 compliant and implements all the rfc 821 SMTP
 * commands except TURN which will always return a not implemented
 * error. SMTP also provides some utility methods for sending mail
 * to an SMTP server.
 * original author: Chris Ryan
 */

class SMTP {
  /**
   *  SMTP server port
   *  @var int
   */
  public $SMTP_PORT = 25;

  /**
   *  SMTP reply line ending
   *  @var string
   */
  public $CRLF = "\r\n";

  /**
   *  Sets whether debugging is turned on
   *  @var bool
   */
  public $do_debug;       // the level of debug to perform

  /**
   *  Sets VERP use on/off (default is off)
   *  @var bool
   */
  public $do_verp = false;

  /**
   * Sets the SMTP PHPMailer Version number
   * @var string
   */
  public $Version         = '5.2.1';

  /////////////////////////////////////////////////
  // PROPERTIES, PRIVATE AND PROTECTED
  /////////////////////////////////////////////////

  private $smtp_conn; // the socket to the server
  private $error;     // error if any on the last call
  private $helo_rply; // the reply the server sent to us for HELO

  /**
   * Initialize the class so that the data is in a known state.
   * @access public
   * @return void
   */
  public function __construct() {
    $this->smtp_conn = 0;
    $this->error = null;
    $this->helo_rply = null;

    $this->do_debug = 0;
  }

  /////////////////////////////////////////////////
  // CONNECTION FUNCTIONS
  /////////////////////////////////////////////////

  /**
   * Connect to the server specified on the port specified.
   * If the port is not specified use the default SMTP_PORT.
   * If tval is specified then a connection will try and be
   * established with the server for that number of seconds.
   * If tval is not specified the default is 30 seconds to
   * try on the connection.
   *
   * SMTP CODE SUCCESS: 220
   * SMTP CODE FAILURE: 421
   * @access public
   * @return bool
   */
  public function Connect($host, $port = 0, $tval = 30) {
    // set the error val to null so there is no confusion
    $this->error = null;

    // make sure we are __not__ connected
    if($this->connected()) {
      // already connected, generate error
      $this->error = array("error" => "Already connected to a server");
      return false;
    }

    if(empty($port)) {
      $port = $this->SMTP_PORT;
    }

    // connect to the smtp server
    $this->smtp_conn = @fsockopen($host,    // the host of the server
                                 $port,    // the port to use
                                 $errno,   // error number if any
                                 $errstr,  // error message if any
                                 $tval);   // give up after ? secs
    // verify we connected properly
    if(empty($this->smtp_conn)) {
      $this->error = array("error" => "Failed to connect to server",
                           "errno" => $errno,
                           "errstr" => $errstr);
      if($this->do_debug >= 1) {
        echo "SMTP -> ERROR: " . $this->error["error"] . ": $errstr ($errno)" . $this->CRLF . '<br />';
      }
      return false;
    }

    // SMTP server can take longer to respond, give longer timeout for first read
    // Windows does not have support for this timeout function
    if(substr(PHP_OS, 0, 3) != "WIN") {
     $max = ini_get('max_execution_time');
     if ($max != 0 && $tval > $max) { // don't bother if unlimited
      @set_time_limit($tval);
     }
     socket_set_timeout($this->smtp_conn, $tval, 0);
    }

    // get any announcement
    $announce = $this->get_lines();

    if($this->do_debug >= 2) {
      echo "SMTP -> FROM SERVER:" . $announce . $this->CRLF . '<br />';
    }

    return true;
  }

  /**
   * Initiate a TLS communication with the server.
   *
   * SMTP CODE 220 Ready to start TLS
   * SMTP CODE 501 Syntax error (no parameters allowed)
   * SMTP CODE 454 TLS not available due to temporary reason
   * @access public
   * @return bool success
   */
  public function StartTLS() {
    $this->error = null; # to avoid confusion

    if(!$this->connected()) {
      $this->error = array("error" => "Called StartTLS() without being connected");
      return false;
    }

    fputs($this->smtp_conn,"STARTTLS" . $this->CRLF);

    $rply = $this->get_lines();
    $code = substr($rply,0,3);

    if($this->do_debug >= 2) {
      echo "SMTP -> FROM SERVER:" . $rply . $this->CRLF . '<br />';
    }

    if($code != 220) {
      $this->error =
         array("error"     => "STARTTLS not accepted from server",
               "smtp_code" => $code,
               "smtp_msg"  => substr($rply,4));
      if($this->do_debug >= 1) {
        echo "SMTP -> ERROR: " . $this->error["error"] . ": " . $rply . $this->CRLF . '<br />';
      }
      return false;
    }

    // Begin encrypted connection
    if(!stream_socket_enable_crypto($this->smtp_conn, true, STREAM_CRYPTO_METHOD_TLS_CLIENT)) {
      return false;
    }

    return true;
  }

  /**
   * Performs SMTP authentication.  Must be run after running the
   * Hello() method.  Returns true if successfully authenticated.
   * @access public
   * @return bool
   */
  public function Authenticate($username, $password, $authtype='LOGIN', $realm='',
                               $workstation='') {
    if (empty($authtype)) {
      $authtype = 'LOGIN';
    }

    switch ($authtype) {
      case 'LOGIN':
        // Start authentication
        fputs($this->smtp_conn,"AUTH LOGIN" . $this->CRLF);
    
        $rply = $this->get_lines();
        $code = substr($rply,0,3);
    
        if($code != 334) {
          $this->error =
            array("error" => "AUTH not accepted from server",
                  "smtp_code" => $code,
                  "smtp_msg" => substr($rply,4));
          if($this->do_debug >= 1) {
            echo "SMTP -> ERROR: " . $this->error["error"] . ": " . $rply . $this->CRLF . '<br />';
          }
          return false;
        }
    
        // Send encoded username
        fputs($this->smtp_conn, base64_encode($username) . $this->CRLF);
    
        $rply = $this->get_lines();
        $code = substr($rply,0,3);
    
        if($code != 334) {
          $this->error =
            array("error" => "Username not accepted from server",
                  "smtp_code" => $code,
                  "smtp_msg" => substr($rply,4));
          if($this->do_debug >= 1) {
            echo "SMTP -> ERROR: " . $this->error["error"] . ": " . $rply . $this->CRLF . '<br />';
          }
          return false;
        }
    
        // Send encoded password
        fputs($this->smtp_conn, base64_encode($password) . $this->CRLF);
    
        $rply = $this->get_lines();
        $code = substr($rply,0,3);
    
        if($code != 235) {
          $this->error =
            array("error" => "Password not accepted from server",
                  "smtp_code" => $code,
                  "smtp_msg" => substr($rply,4));
          if($this->do_debug >= 1) {
            echo "SMTP -> ERROR: " . $this->error["error"] . ": " . $rply . $this->CRLF . '<br />';
          }
          return false;
        }
        break;
      case 'NTLM':
        /*
         * ntlm_sasl_client.php
         ** Bundled with Permission
         **
         ** How to telnet in windows: http://technet.microsoft.com/en-us/library/aa995718%28EXCHG.65%29.aspx
         ** PROTOCOL Documentation http://curl.haxx.se/rfc/ntlm.html#ntlmSmtpAuthentication
         */
        require_once('ntlm_sasl_client.php');
        $temp = new stdClass();
        $ntlm_client = new ntlm_sasl_client_class;
        if(! $ntlm_client->Initialize($temp)){//let's test if every function its available
            $this->error = array("error" => $temp->error);
            if($this->do_debug >= 1) {
                echo "You need to enable some modules in your php.ini file: " . $this->error["error"] . $this->CRLF;
            }
            return false;
        }
        $msg1 = $ntlm_client->TypeMsg1($realm, $workstation);//msg1
        
        fputs($this->smtp_conn,"AUTH NTLM " . base64_encode($msg1) . $this->CRLF);

        $rply = $this->get_lines();
        $code = substr($rply,0,3);
        

        if($code != 334) {
            $this->error =
                array("error" => "AUTH not accepted from server",
                      "smtp_code" => $code,
                      "smtp_msg" => substr($rply,4));
            if($this->do_debug >= 1) {
                echo "SMTP -> ERROR: " . $this->error["error"] .
                         ": " . $rply . $this->CRLF;
            }
            return false;
        }
        
        $challange = substr($rply,3);//though 0 based, there is a white space after the 3 digit number....//msg2
        $challange = base64_decode($challange);
        $ntlm_res = $ntlm_client->NTLMResponse(substr($challange,24,8),$password);
        $msg3 = $ntlm_client->TypeMsg3($ntlm_res,$username,$realm,$workstation);//msg3
        // Send encoded username
        fputs($this->smtp_conn, base64_encode($msg3) . $this->CRLF);

        $rply = $this->get_lines();
        $code = substr($rply,0,3);

        if($code != 235) {
            $this->error =
                array("error" => "Could not authenticate",
                      "smtp_code" => $code,
                      "smtp_msg" => substr($rply,4));
            if($this->do_debug >= 1) {
                echo "SMTP -> ERROR: " . $this->error["error"] .
                         ": " . $rply . $this->CRLF;
            }
            return false;
        }
        break;
    }
    return true;
  }

  /**
   * Returns true if connected to a server otherwise false
   * @access public
   * @return bool
   */
  public function Connected() {
    if(!empty($this->smtp_conn)) {
      $sock_status = socket_get_status($this->smtp_conn);
      if($sock_status["eof"]) {
        // the socket is valid but we are not connected
        if($this->do_debug >= 1) {
            echo "SMTP -> NOTICE:" . $this->CRLF . "EOF caught while checking if connected";
        }
        $this->Close();
        return false;
      }
      return true; // everything looks good
    }
    return false;
  }

  /**
   * Closes the socket and cleans up the state of the class.
   * It is not considered good to use this function without
   * first trying to use QUIT.
   * @access public
   * @return void
   */
  public function Close() {
    $this->error = null; // so there is no confusion
    $this->helo_rply = null;
    if(!empty($this->smtp_conn)) {
      // close the connection and cleanup
      fclose($this->smtp_conn);
      $this->smtp_conn = 0;
    }
  }

  /////////////////////////////////////////////////
  // SMTP COMMANDS
  /////////////////////////////////////////////////

  /**
   * Issues a data command and sends the msg_data to the server
   * finializing the mail transaction. $msg_data is the message
   * that is to be send with the headers. Each header needs to be
   * on a single line followed by a <CRLF> with the message headers
   * and the message body being seperated by and additional <CRLF>.
   *
   * Implements rfc 821: DATA <CRLF>
   *
   * SMTP CODE INTERMEDIATE: 354
   *     [data]
   *     <CRLF>.<CRLF>
   *     SMTP CODE SUCCESS: 250
   *     SMTP CODE FAILURE: 552,554,451,452
   * SMTP CODE FAILURE: 451,554
   * SMTP CODE ERROR  : 500,501,503,421
   * @access public
   * @return bool
   */
  public function Data($msg_data) {
    $this->error = null; // so no confusion is caused

    if(!$this->connected()) {
      $this->error = array(
              "error" => "Called Data() without being connected");
      return false;
    }

    fputs($this->smtp_conn,"DATA" . $this->CRLF);

    $rply = $this->get_lines();
    $code = substr($rply,0,3);

    if($this->do_debug >= 2) {
      echo "SMTP -> FROM SERVER:" . $rply . $this->CRLF . '<br />';
    }

    if($code != 354) {
      $this->error =
        array("error" => "DATA command not accepted from server",
              "smtp_code" => $code,
              "smtp_msg" => substr($rply,4));
      if($this->do_debug >= 1) {
        echo "SMTP -> ERROR: " . $this->error["error"] . ": " . $rply . $this->CRLF . '<br />';
      }
      return false;
    }

    /* the server is ready to accept data!
     * according to rfc 821 we should not send more than 1000
     * including the CRLF
     * characters on a single line so we will break the data up
     * into lines by \r and/or \n then if needed we will break
     * each of those into smaller lines to fit within the limit.
     * in addition we will be looking for lines that start with
     * a period '.' and append and additional period '.' to that
     * line. NOTE: this does not count towards limit.
     */

    // normalize the line breaks so we know the explode works
    $msg_data = str_replace("\r\n","\n",$msg_data);
    $msg_data = str_replace("\r","\n",$msg_data);
    $lines = explode("\n",$msg_data);

    /* we need to find a good way to determine is headers are
     * in the msg_data or if it is a straight msg body
     * currently I am assuming rfc 822 definitions of msg headers
     * and if the first field of the first line (':' sperated)
     * does not contain a space then it _should_ be a header
     * and we can process all lines before a blank "" line as
     * headers.
     */

    $field = substr($lines[0],0,strpos($lines[0],":"));
    $in_headers = false;
    if(!empty($field) && !strstr($field," ")) {
      $in_headers = true;
    }

    $max_line_length = 998; // used below; set here for ease in change

    while(list(,$line) = @each($lines)) {
      $lines_out = null;
      if($line == "" && $in_headers) {
        $in_headers = false;
      }
      // ok we need to break this line up into several smaller lines
      while(strlen($line) > $max_line_length) {
        $pos = strrpos(substr($line,0,$max_line_length)," ");

        // Patch to fix DOS attack
        if(!$pos) {
          $pos = $max_line_length - 1;
          $lines_out[] = substr($line,0,$pos);
          $line = substr($line,$pos);
        } else {
          $lines_out[] = substr($line,0,$pos);
          $line = substr($line,$pos + 1);
        }

        /* if processing headers add a LWSP-char to the front of new line
         * rfc 822 on long msg headers
         */
        if($in_headers) {
          $line = "\t" . $line;
        }
      }
      $lines_out[] = $line;

      // send the lines to the server
      while(list(,$line_out) = @each($lines_out)) {
        if(strlen($line_out) > 0)
        {
          if(substr($line_out, 0, 1) == ".") {
            $line_out = "." . $line_out;
          }
        }
        fputs($this->smtp_conn,$line_out . $this->CRLF);
      }
    }

    // message data has been sent
    fputs($this->smtp_conn, $this->CRLF . "." . $this->CRLF);

    $rply = $this->get_lines();
    $code = substr($rply,0,3);

    if($this->do_debug >= 2) {
      echo "SMTP -> FROM SERVER:" . $rply . $this->CRLF . '<br />';
    }

    if($code != 250) {
      $this->error =
        array("error" => "DATA not accepted from server",
              "smtp_code" => $code,
              "smtp_msg" => substr($rply,4));
      if($this->do_debug >= 1) {
        echo "SMTP -> ERROR: " . $this->error["error"] . ": " . $rply . $this->CRLF . '<br />';
      }
      return false;
    }
    return true;
  }

  /**
   * Sends the HELO command to the smtp server.
   * This makes sure that we and the server are in
   * the same known state.
   *
   * Implements from rfc 821: HELO <SP> <domain> <CRLF>
   *
   * SMTP CODE SUCCESS: 250
   * SMTP CODE ERROR  : 500, 501, 504, 421
   * @access public
   * @return bool
   */
  public function Hello($host = '') {
    $this->error = null; // so no confusion is caused

    if(!$this->connected()) {
      $this->error = array(
            "error" => "Called Hello() without being connected");
      return false;
    }

    // if hostname for HELO was not specified send default
    if(empty($host)) {
      // determine appropriate default to send to server
      $host = "localhost";
    }

    // Send extended hello first (RFC 2821)
    if(!$this->SendHello("EHLO", $host)) {
      if(!$this->SendHello("HELO", $host)) {
        return false;
      }
    }

    return true;
  }

  /**
   * Sends a HELO/EHLO command.
   * @access private
   * @return bool
   */
  private function SendHello($hello, $host) {
    fputs($this->smtp_conn, $hello . " " . $host . $this->CRLF);

    $rply = $this->get_lines();
    $code = substr($rply,0,3);

    if($this->do_debug >= 2) {
      echo "SMTP -> FROM SERVER: " . $rply . $this->CRLF . '<br />';
    }

    if($code != 250) {
      $this->error =
        array("error" => $hello . " not accepted from server",
              "smtp_code" => $code,
              "smtp_msg" => substr($rply,4));
      if($this->do_debug >= 1) {
        echo "SMTP -> ERROR: " . $this->error["error"] . ": " . $rply . $this->CRLF . '<br />';
      }
      return false;
    }

    $this->helo_rply = $rply;

    return true;
  }

  /**
   * Starts a mail transaction from the email address specified in
   * $from. Returns true if successful or false otherwise. If True
   * the mail transaction is started and then one or more Recipient
   * commands may be called followed by a Data command.
   *
   * Implements rfc 821: MAIL <SP> FROM:<reverse-path> <CRLF>
   *
   * SMTP CODE SUCCESS: 250
   * SMTP CODE SUCCESS: 552,451,452
   * SMTP CODE SUCCESS: 500,501,421
   * @access public
   * @return bool
   */
  public function Mail($from) {
    $this->error = null; // so no confusion is caused

    if(!$this->connected()) {
      $this->error = array(
              "error" => "Called Mail() without being connected");
      return false;
    }

    $useVerp = ($this->do_verp ? "XVERP" : "");
    fputs($this->smtp_conn,"MAIL FROM:<" . $from . ">" . $useVerp . $this->CRLF);

    $rply = $this->get_lines();
    $code = substr($rply,0,3);

    if($this->do_debug >= 2) {
      echo "SMTP -> FROM SERVER:" . $rply . $this->CRLF . '<br />';
    }

    if($code != 250) {
      $this->error =
        array("error" => "MAIL not accepted from server",
              "smtp_code" => $code,
              "smtp_msg" => substr($rply,4));
      if($this->do_debug >= 1) {
        echo "SMTP -> ERROR: " . $this->error["error"] . ": " . $rply . $this->CRLF . '<br />';
      }
      return false;
    }
    return true;
  }

  /**
   * Sends the quit command to the server and then closes the socket
   * if there is no error or the $close_on_error argument is true.
   *
   * Implements from rfc 821: QUIT <CRLF>
   *
   * SMTP CODE SUCCESS: 221
   * SMTP CODE ERROR  : 500
   * @access public
   * @return bool
   */
  public function Quit($close_on_error = true) {
    $this->error = null; // so there is no confusion

    if(!$this->connected()) {
      $this->error = array(
              "error" => "Called Quit() without being connected");
      return false;
    }

    // send the quit command to the server
    fputs($this->smtp_conn,"quit" . $this->CRLF);

    // get any good-bye messages
    $byemsg = $this->get_lines();

    if($this->do_debug >= 2) {
      echo "SMTP -> FROM SERVER:" . $byemsg . $this->CRLF . '<br />';
    }

    $rval = true;
    $e = null;

    $code = substr($byemsg,0,3);
    if($code != 221) {
      // use e as a tmp var cause Close will overwrite $this->error
      $e = array("error" => "SMTP server rejected quit command",
                 "smtp_code" => $code,
                 "smtp_rply" => substr($byemsg,4));
      $rval = false;
      if($this->do_debug >= 1) {
        echo "SMTP -> ERROR: " . $e["error"] . ": " . $byemsg . $this->CRLF . '<br />';
      }
    }

    if(empty($e) || $close_on_error) {
      $this->Close();
    }

    return $rval;
  }

  /**
   * Sends the command RCPT to the SMTP server with the TO: argument of $to.
   * Returns true if the recipient was accepted false if it was rejected.
   *
   * Implements from rfc 821: RCPT <SP> TO:<forward-path> <CRLF>
   *
   * SMTP CODE SUCCESS: 250,251
   * SMTP CODE FAILURE: 550,551,552,553,450,451,452
   * SMTP CODE ERROR  : 500,501,503,421
   * @access public
   * @return bool
   */
  public function Recipient($to) {
    $this->error = null; // so no confusion is caused

    if(!$this->connected()) {
      $this->error = array(
              "error" => "Called Recipient() without being connected");
      return false;
    }

    fputs($this->smtp_conn,"RCPT TO:<" . $to . ">" . $this->CRLF);

    $rply = $this->get_lines();
    $code = substr($rply,0,3);

    if($this->do_debug >= 2) {
      echo "SMTP -> FROM SERVER:" . $rply . $this->CRLF . '<br />';
    }

    if($code != 250 && $code != 251) {
      $this->error =
        array("error" => "RCPT not accepted from server",
              "smtp_code" => $code,
              "smtp_msg" => substr($rply,4));
      if($this->do_debug >= 1) {
        echo "SMTP -> ERROR: " . $this->error["error"] . ": " . $rply . $this->CRLF . '<br />';
      }
      return false;
    }
    return true;
  }

  /**
   * Sends the RSET command to abort and transaction that is
   * currently in progress. Returns true if successful false
   * otherwise.
   *
   * Implements rfc 821: RSET <CRLF>
   *
   * SMTP CODE SUCCESS: 250
   * SMTP CODE ERROR  : 500,501,504,421
   * @access public
   * @return bool
   */
  public function Reset() {
    $this->error = null; // so no confusion is caused

    if(!$this->connected()) {
      $this->error = array(
              "error" => "Called Reset() without being connected");
      return false;
    }

    fputs($this->smtp_conn,"RSET" . $this->CRLF);

    $rply = $this->get_lines();
    $code = substr($rply,0,3);

    if($this->do_debug >= 2) {
      echo "SMTP -> FROM SERVER:" . $rply . $this->CRLF . '<br />';
    }

    if($code != 250) {
      $this->error =
        array("error" => "RSET failed",
              "smtp_code" => $code,
              "smtp_msg" => substr($rply,4));
      if($this->do_debug >= 1) {
        echo "SMTP -> ERROR: " . $this->error["error"] . ": " . $rply . $this->CRLF . '<br />';
      }
      return false;
    }

    return true;
  }

  /**
   * Starts a mail transaction from the email address specified in
   * $from. Returns true if successful or false otherwise. If True
   * the mail transaction is started and then one or more Recipient
   * commands may be called followed by a Data command. This command
   * will send the message to the users terminal if they are logged
   * in and send them an email.
   *
   * Implements rfc 821: SAML <SP> FROM:<reverse-path> <CRLF>
   *
   * SMTP CODE SUCCESS: 250
   * SMTP CODE SUCCESS: 552,451,452
   * SMTP CODE SUCCESS: 500,501,502,421
   * @access public
   * @return bool
   */
  public function SendAndMail($from) {
    $this->error = null; // so no confusion is caused

    if(!$this->connected()) {
      $this->error = array(
          "error" => "Called SendAndMail() without being connected");
      return false;
    }

    fputs($this->smtp_conn,"SAML FROM:" . $from . $this->CRLF);

    $rply = $this->get_lines();
    $code = substr($rply,0,3);

    if($this->do_debug >= 2) {
      echo "SMTP -> FROM SERVER:" . $rply . $this->CRLF . '<br />';
    }

    if($code != 250) {
      $this->error =
        array("error" => "SAML not accepted from server",
              "smtp_code" => $code,
              "smtp_msg" => substr($rply,4));
      if($this->do_debug >= 1) {
        echo "SMTP -> ERROR: " . $this->error["error"] . ": " . $rply . $this->CRLF . '<br />';
      }
      return false;
    }
    return true;
  }

  /**
   * This is an optional command for SMTP that this class does not
   * support. This method is here to make the RFC821 Definition
   * complete for this class and __may__ be implimented in the future
   *
   * Implements from rfc 821: TURN <CRLF>
   *
   * SMTP CODE SUCCESS: 250
   * SMTP CODE FAILURE: 502
   * SMTP CODE ERROR  : 500, 503
   * @access public
   * @return bool
   */
  public function Turn() {
    $this->error = array("error" => "This method, TURN, of the SMTP ".
                                    "is not implemented");
    if($this->do_debug >= 1) {
      echo "SMTP -> NOTICE: " . $this->error["error"] . $this->CRLF . '<br />';
    }
    return false;
  }

  /**
  * Get the current error
  * @access public
  * @return array
  */
  public function getError() {
    return $this->error;
  }

  /////////////////////////////////////////////////
  // INTERNAL FUNCTIONS
  /////////////////////////////////////////////////

  /**
   * Read in as many lines as possible
   * either before eof or socket timeout occurs on the operation.
   * With SMTP we can tell if we have more lines to read if the
   * 4th character is '-' symbol. If it is a space then we don't
   * need to read anything else.
   * @access private
   * @return string
   */
  private function get_lines() {
    $data = "";
    while(!feof($this->smtp_conn)) {
      $str = @fgets($this->smtp_conn,515);
      if($this->do_debug >= 4) {
        echo "SMTP -> get_lines(): \$data was \"$data\"" . $this->CRLF . '<br />';
        echo "SMTP -> get_lines(): \$str is \"$str\"" . $this->CRLF . '<br />';
      }
      $data .= $str;
      if($this->do_debug >= 4) {
        echo "SMTP -> get_lines(): \$data is \"$data\"" . $this->CRLF . '<br />';
      }
      // if 4th character is a space, we are done reading, break the loop
      if(substr($str,3,1) == " ") { break; }
    }
    return $data;
  }

}

?>