<?php
/*~ class.smtp.php
.---------------------------------------------------------------------------.
|  Software: PHPMailer - PHP email class                                    |
|   Version: 2.1                                                            |
|   Contact: via sourceforge.net support pages (also www.codeworxtech.com)  |
|      Info: http://phpmailer.sourceforge.net                               |
|   Support: http://sourceforge.net/projects/phpmailer/                     |
| ------------------------------------------------------------------------- |
|    Author: Andy Prevost (project admininistrator)                         |
|    Author: Brent R. Matzelle (original founder)                           |
| Copyright (c) 2004-2007, 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.                                         |
| ------------------------------------------------------------------------- |
| We offer a number of paid services (www.codeworxtech.com):                |
| - Web Hosting on highly optimized fast and secure servers                 |
| - Technology Consulting                                                   |
| - Oursourcing (highly qualified programmers and graphic designers)        |
'---------------------------------------------------------------------------'

/**
 * 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.
 * @package PHPMailer
 * @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;

  /**#@+
   * @access private
   */
  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;
  }

  /**
   * @return null|array
   */
  public function getError()
  {
    return $this->error;
  }

  /*************************************************************
   *                    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()) {
      /* ok we are connected! what should we do?
       * for now we will just give an error saying we
       * are already connected
       */
      $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;
      }
      return false;
    }

    /* sometimes the SMTP server takes a little longer to respond
     * so we will give it a longer timeout for the first read
     * - Windows still does not have support for this timeout function
     */
    if(substr(PHP_OS, 0, 3) != "WIN")
      stream_set_timeout($this->smtp_conn,$tval);

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

    /* set the timeout  of any socket functions at 1/10 of a second */
    //if(function_exists("socket_set_timeout"))
    //   socket_set_timeout($this->smtp_conn, 0, 100000);

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

    return true;
  }

  /**
   * Initiate a TSL 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() {
    $extra = '';
    $this->error = null; # to avoid confusion

    if(!$this->connected()) {
      $this->error = array("error" => "Called StartTLS() without being connected");
      return false;
    }
    fwrite($this->smtp_conn, "STARTTLS" . $extra . $this->CRLF);

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

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

    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;
      }
      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, $password) {
    // Start authentication
    fwrite($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;
      }
      return false;
    }

    // Send encoded username
    fwrite($this->smtp_conn, base64_encode($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;
      }
      return false;
    }

    // Send encoded password
    fwrite($this->smtp_conn, base64_encode($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;
      }
      return false;
    }

    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($sock_status["eof"]) {
        // hmm this is an odd situation... the socket is
        // valid but we are not connected anymore
        if($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;
    }

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

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

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

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

      // now 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 = "." . $line_out;
          }
        }
        fwrite($this->smtp_conn,$line_out . $this->CRLF);
      }
    }

    // ok all the message data has been sent so lets get this
    // over with aleady
    fwrite($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:" . $this->CRLF . $rply;
    }

    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;
      }
      return false;
    }
    return true;
  }

  /**
   * Expand takes the name and asks the server to list all the
   * people who are members of the _list_. Expand will return
   * back and array of the result or false if an error occurs.
   * Each value in the array returned has the format of:
   *     [ <full-name> <sp> ] <path>
   * The definition of <path> is defined in rfc 821
   *
   * Implements rfc 821: EXPN <SP> <string> <CRLF>
   *
   * SMTP CODE SUCCESS: 250
   * SMTP CODE FAILURE: 550
   * SMTP CODE ERROR  : 500,501,502,504,421
   * @access public
   * @return string array
   */
  public function Expand($name) {
    $this->error = null; // so no confusion is caused

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

    fwrite($this->smtp_conn,"EXPN " . $name . $this->CRLF);

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

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

    if($code != 250) {
      $this->error =
        array("error" => "EXPN 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;
    }

    // parse the reply and place in our array to return to user
    $entries = explode($this->CRLF,$rply);
    foreach ($entries as $l) {
      $list[] = substr($l,4);
    }

    return $list;
  }

  /**
   * 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 a hostname for the HELO was not specified determine
    //a suitable one to send
    if(empty($host)) {
      // we need to determine some sort of appopiate default
      // to send to the 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, $host) {
    fwrite($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: " . $this->CRLF . $rply;
    }

    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;
      }
      return false;
    }

    $this->helo_rply = $rply;

    return true;
  }

  /**
   * Gets help information on the keyword specified. If the keyword
   * is not specified then returns generic help, ussually contianing
   * A list of keywords that help is available on. This function
   * returns the results back to the user. It is up to the user to
   * handle the returned data. If an error occurs then false is
   * returned with $this->error set appropiately.
   *
   * Implements rfc 821: HELP [ <SP> <string> ] <CRLF>
   *
   * SMTP CODE SUCCESS: 211,214
   * SMTP CODE ERROR  : 500,501,502,504,421
   * @access public
   * @return string
   */
  public function Help($keyword="") {
    $this->error = null; // to avoid confusion

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

    $extra = "";
    if(!empty($keyword)) {
      $extra = " " . $keyword;
    }

    fwrite($this->smtp_conn,"HELP" . $extra . $this->CRLF);

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

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

    if($code != 211 && $code != 214) {
      $this->error =
        array("error" => "HELP 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;
    }

    return $rply;
  }

  /**
   * 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" : "");
    if(strpos($from,'<') === false || strpos($from,'>') === false || substr(trim($from),-1) !== '>'){
      fwrite($this->smtp_conn, 'MAIL FROM:<' . $from . '>' . $useVerp . $this->CRLF);
    }
    else {
      $from = substr($from, strpos($from,'<'));
      fwrite($this->smtp_conn, 'MAIL FROM:' . trim($from)  . $useVerp . $this->CRLF);
    }

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

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

    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;
      }
      return false;
    }
    return true;
  }

  /**
   * Sends the command NOOP to the SMTP server.
   *
   * Implements from rfc 821: NOOP <CRLF>
   *
   * SMTP CODE SUCCESS: 250
   * SMTP CODE ERROR  : 500, 421
   * @access public
   * @return bool
   */
  public function Noop() {
    $this->error = null; // so no confusion is caused

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

    fwrite($this->smtp_conn,"NOOP" . $this->CRLF);

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

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

    if($code != 250) {
      $this->error =
        array("error" => "NOOP 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;
    }
    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
    fwrite($this->smtp_conn,"quit" . $this->CRLF);

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

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

    $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;
      }
    }

    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;
    }

    fwrite($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:" . $this->CRLF . $rply;
    }

    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;
      }
      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;
    }

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

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

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

    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;
      }
      return false;
    }

    return true;
  }

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

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

    fwrite($this->smtp_conn,"SEND FROM:" . $from . $this->CRLF);

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

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

    if($code != 250) {
      $this->error =
        array("error" => "SEND 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;
    }
    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;
    }

    fwrite($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:" . $this->CRLF . $rply;
    }

    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;
      }
      return false;
    }
    return true;
  }

  /**
   * Starts a mail transaction from the email address specified in
   * $from. Returns true if successful or false otherwise. If True
   * the mail transaction is started and then one or more Recipient
   * commands may be called followed by a Data command. This command
   * will send the message to the users terminal if they are logged
   * in or mail it to them if they are not.
   *
   * Implements rfc 821: SOML <SP> FROM:<reverse-path> <CRLF>
   *
   * SMTP CODE SUCCESS: 250
   * SMTP CODE SUCCESS: 552,451,452
   * SMTP CODE SUCCESS: 500,501,502,421
   * @access public
   * @return bool
   */
  public function SendOrMail($from) {
    $this->error = null; // so no confusion is caused

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

    fwrite($this->smtp_conn,"SOML FROM:" . $from . $this->CRLF);

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

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

    if($code != 250) {
      $this->error =
        array("error" => "SOML 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;
    }
    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;
    }
    return false;
  }

  /**
   * Verifies that the name is recognized by the server.
   * Returns false if the name could not be verified otherwise
   * the response from the server is returned.
   *
   * Implements rfc 821: VRFY <SP> <string> <CRLF>
   *
   * SMTP CODE SUCCESS: 250,251
   * SMTP CODE FAILURE: 550,551,553
   * SMTP CODE ERROR  : 500,501,502,421
   * @access public
   * @return int
   */
  public function Verify($name) {
    $this->error = null; // so no confusion is caused

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

    fwrite($this->smtp_conn,"VRFY " . $name . $this->CRLF);

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

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

    if($code != 250 && $code != 251) {
      $this->error =
        array("error" => "VRFY failed on name '$name'",
              "smtp_code" => $code,
              "smtp_msg" => substr($rply,4));
      if($this->do_debug >= 1) {
        echo "SMTP -> ERROR: " . $this->error["error"] .
                 ": " . $rply . $this->CRLF;
      }
      return false;
    }
    return $rply;
  }

  /*******************************************************************
   *                       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() {
    $data = "";
    while($str = @fgets($this->smtp_conn,515)) {
      if($this->do_debug >= 4) {
        echo "SMTP -> get_lines(): \$data was \"$data\"" .
                 $this->CRLF;
        echo "SMTP -> get_lines(): \$str is \"$str\"" .
                 $this->CRLF;
      }
      $data .= $str;
      if($this->do_debug >= 4) {
        echo "SMTP -> get_lines(): \$data is \"$data\"" . $this->CRLF;
      }
      // if the 4th character is a space then we are done reading
      // so just break the loop
      if(substr($str,3,1) == " ") { break; }
    }
    return $data;
  }

}