PHP mail sending class (smtp method or mail function method)

<?php 
/**
* 邮件发送类
* by bbs.it-home.org
*/
Class sendmail{ 

    public $smtp_host; 
    public $smtp_port = 25; 
    public $smtp_user; 
    public $smtp_password; 
    public $from_name; 
    public $SendFromMail; 
    public $mail_to; 
    public $subject; 
    public $message; 
    public $headers = ''; 
    public $ContentType = 'html'; 
    public $charset = 'windows-1251'; 
    public $smtp_debug = true; 
    public $socket; 
    public $error; 
    public $SendMailVia  = 'smtp'; 
     
  public function __construct() 
    { 
            if($this->SendFromMail == ''){ 
               $this->SendFromMail = $this->smtp_user; 
            } 
    } 
     
    public function Send($mail_to = '', $subject = '', $message = '') 
    { 
        if($mail_to!=''){$this->mail_to = stripslashes($mail_to);} 
            if($subject!=''){$this->subject = stripslashes($subject);} 
            if($message!=''){$this->message = $message;} 
            $meilsArr = array_filter($this->GetMailAndNameArr()); 
            if(trim($this->mail_to)==''){$this->error = 'Enter the recipient address'; } 
            if($meilsArr == array()){$this->error = 'Please enter a valid recipient address'; } 
            foreach ($meilsArr as $val) 
            { 
                $validEmail = $this->validEmail($val[2]); 
                if($validEmail) 
                { 
                  if($this->SendMailVia=='smtp'){ 
                      return $this->SMTPsend($mail_to = $val[2], $name_to = $val[1]); 
                    } 
                    else{ 
                      return $this->MAILsend($mail_to = $val[2], $name_to = $val[1]); 
                    }     
                } 
            } 
    } 
     
    public function MAILsend($mail_to, $name_to) 
    { 
    if($this->ContentType=="text"){ 
        $header="Content-Type: text/plain; charset=".$this->charset.""; 
      } 
        else{ 
        $header="Return-Path: ".$this->smtp_user."\n". 
      "Reply-To: ".$this->SendFromMail."\n". 
      "From: ".$this->from_name." <".$this->SendFromMail.">\n". 
      "Subject: ".$this->subject."\n". 
        "Content-Type: text/html; charset=".$this->charset."\n"; 
      } 
      if(mail("$name_to <$mail_to>",$this->subject,$this->message,$header)){ 
         return true; 
        }else{ 
         return false; 
        } 
  } 
     
    public function SMTPsend($mail_to, $name_to) 
    { 
            $SEND =   "Date: ".date("D, d M Y H:i:s") . "\r\n"; 
            $SEND .=   'Subject: =?'.$this->charset.'?B?'.base64_encode($this->subject)."=?=\r\n"; 
            if ($this->headers!=''){ $SEND .= $this->headers."\r\n\r\n"; } 
      else 
      { 
         $SEND .= "Reply-To: ".$this->SendFromMail."\r\n"; 
         $SEND .= "MIME-Version: 1.0\r\n"; 
         $SEND .= "Content-Type: text/".$this->ContentType."; charset=\"".$this->charset."\"\r\n"; 
         $SEND .= "Content-Transfer-Encoding: 8bit\r\n"; 
         $SEND .= "From: \"".$this->from_name."\" <".$this->SendFromMail.">\r\n"; 
         $SEND .= "To: $name_to <$mail_to>\r\n"; 
         $SEND .= "X-Priority: 3\r\n\r\n"; 
      } 
      $SEND .=  $this->message."\r\n"; 
         
                $socket = fsockopen($this->smtp_host, $this->smtp_port, $errno, $errstr, 30); 
          if(!socket) 
            { 
          if($this->smtp_debug) $this->error = $errno." - ".$errstr; 
          return false; 
        } 
                 
                if (!$this->server_parse($socket, "220", __LINE__)){ return false; } 
                 
            fputs($socket, "HELO ".$this->smtp_host. "\r\n"); 
            if (!$this->server_parse($socket, "250", __LINE__)) { 
               if ($this->smtp_debug) $this->error = '<p>Can not send HELO!</p>'; 
               fclose($socket); 
               return false; 
            } 
            fputs($socket, "AUTH LOGIN\r\n"); 
            if (!$this->server_parse($socket, "334", __LINE__)) { 
               if ($this->smtp_debug) $this->error = '<p>Can not find an answer to a request authorization.</p>'; 
               fclose($socket); 
               return false; 
            } 
            fputs($socket, base64_encode($this->smtp_user) . "\r\n"); 
            if (!$this->server_parse($socket, "334", __LINE__)) { 
               if ($this->smtp_debug) $this->error = '<p>Login authorization was not accepted by server!</p>'; 
               fclose($socket); 
               return false; 
            } 
            fputs($socket, base64_encode($this->smtp_password) . "\r\n"); 
            if (!$this->server_parse($socket, "235", __LINE__)) { 
               if ($this->smtp_debug) $this->error = '<p>No password was not accepted as a true server! Authorization Error!</p>'; 
               fclose($socket); 
               return false; 
            } 
            fputs($socket, "MAIL FROM: <".$this->smtp_user.">\r\n"); 
            if (!$this->server_parse($socket, "250", __LINE__)) { 
               if ($this->smtp_debug) $this->error = '<p>Unable to send command MAIL FROM: </p>'; 
               fclose($socket); 
               return false; 
            } 
            fputs($socket, "RCPT TO: <" . $mail_to . ">\r\n"); 
            if (!$this->server_parse($socket, "250", __LINE__)) { 
               if ($this->smtp_debug) $this->error = '<p>Unable to send command RCPT TO: </p>'; 
               fclose($socket); 
               return false; 
            } 
            fputs($socket, "DATA\r\n"); 
            if (!$this->server_parse($socket, "354", __LINE__)) { 
               if ($this->smtp_debug) $this->error = '<p>Unable to send command DATA</p>'; 
               fclose($socket); 
               return false; 
            } 
            fputs($socket, $SEND."\r\n.\r\n"); 
            if (!$this->server_parse($socket, "250", __LINE__)) { 
               if ($this->smtp_debug) $this->error = '<p>Unable to send the message body. The letter was sent!</p>'; 
               fclose($socket); 
               return false; 
            } 
            fputs($socket, "QUIT\r\n"); 
            fclose($socket); 
            return TRUE; 
    } 
       
    private function GetMailAndNameArr(){ 
        $mailingArr = array(); 
            $tos = preg_split("/;|,/",$this->mail_to); 
            $pregcode = '/(.*?)<(.*?)>/i'; 
            foreach($tos as $to) 
            { 
              if(preg_match('/(.*?)<(.*?)>/i',$to,$matches)) 
                { 
                  unset($matches[0]);     
                  $matches[1] = trim(str_replace('"','',$matches[1])); 
                  $matches[2] = trim($matches[2]); 
                  $mailingArr[] =$matches;  
                } 
                elseif(preg_match('/\b([A-Z0-9._%-]+)@([A-Z0-9.-]+\.[A-Z]{2,4})\b/i',$to,$matches2)) 
                { 
                     unset($matches[0]);     
                     $matches[1] = trim(str_replace('"','',$matches2[1])); 
                     $matches[2] = trim($matches2[0]); 
                     $mailingArr[] =$matches; 
                } 
            } 
            return $mailingArr; 
    } 
     
    private function server_parse($socket, $response, $line = __LINE__) { 
    while (substr($server_response, 3, 1) != ' ') { 
          if (!($server_response = fgets($socket, 256))) { 
               if ($this->smtp_debug) $this->error = "<p>$line Problems sending mail! $response</p>"; 
               return false; 
          } 
    } 
    if (!(substr($server_response, 0, 3) == $response)) { 
           if ($this->smtp_debug) $this->error = "<p>$line Problems sending mail! $response</p>"; 
           return false; 
        } 
    return true; 
  } 

  function validEmail($email) 
  { 
    $isValid = true; 
    $atIndex = strrpos($email, "@"); 
      $msg = ''; 
    if (is_bool($atIndex) && !$atIndex) 
    { 
      $isValid = false; 
    } 
    else 
    { 
      $domain = substr($email, $atIndex+1); 
      $local = substr($email, 0, $atIndex); 
      $localLen = strlen($local); 
      $domainLen = strlen($domain); 
      if ($localLen < 1 || $localLen > 64){ 
                 $msg = 'local part length exceeded'; 
         $isValid = false; 
      } 
      else if ($domainLen < 1 || $domainLen > 255){ 
                 $msg = ' domain part length exceeded '; 
         $isValid = false; 
      } 
      else if ($local[0] == '.' || $local[$localLen-1] == '.'){ 
                 $msg = ' local part starts or ends with .'; 
         $isValid = false; 
      } 
      else if (preg_match('/\\.\\./', $local)){ 
                 $msg = 'local part has two consecutive dots'; 
         $isValid = false; 
      } 
      else if (!preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain)){ 
                 $msg = 'character not valid in domain part'; 
         $isValid = false; 
      } 
      else if (preg_match('/\\.\\./', $domain)){ 
                 $msg = '  domain part has two consecutive dots'; 
         $isValid = false; 
      } 
      else if(!preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/', str_replace("\\\\","",$local))){ 
                 $msg = '  character not valid in local part unless local part is quoted'; 
         if (!preg_match('/^"(\\\\"|[^"])+"$/',str_replace("\\\\","",$local))){ 
            $isValid = false; 
         } 
      } 
      if ($isValid && !(checkdnsrr($domain,"MX") || checkdnsrr($domain,"A"))){ 
                 $msg = '  domain <b>'.$domain.'</b> not found in DNS'; 
         $isValid = false; 
      } 
    } 
      $this->error = $msg; 
    return $isValid; 
  } 

} 
?>

<?php  
include "sendmail.class.php"; 
$Mail = new sendmail(); 

// Set congif 
$Mail->SendMailVia = 'smtp';  // Send via smtp server or mail function 
$Mail->smtp_host = 'mail.myhost.com'; 
$Mail->smtp_port = 25; 
$Mail->smtp_user = 'user@myhost.com'; 
$Mail->smtp_password = 'mypassw'; 

// 例1 (mail from me) 
if($Mail->Send('mymail1@mydomain.com; recipient2 name <recipientmail2@mydomain.com>,"recipient name" <recipient@mail.com>',
'My subject','My message here.')) 
{ 
  echo '邮件已发送!'; 
} 
else 
{ 
  echo $Mail->error; 
} 

// 例2 (mail from me) 
$Mail->mail_to = 'mymail1@mydomain.com; recipient2 name <recipientmail2@mydomain.com>,"recipient name" <recipient@mail.com>'; 
$Mail->subject = 'My subject'; 
$Mail->message = 'My message here'; 

if($Mail->Send()) 
{ 
  echo '邮件已发送!'; 
} 
else 
{ 
  echo $Mail->error; 
} 


// 例3 (mail from another user: example user2@site2.com) 

$Mail->mail_to = 'Recipient Name <recipientmail@domain.com>'; 
$Mail->subject = 'My subject'; 
$Mail->message = 'My message here'; 
$Mail->from_name = 'User2 Name'; 
$Mail->SendFromMail = 'user2@site2.com'; 

if($Mail->Send()) 
{ 
  echo 'message Mail send!'; 
} 
else 
{ 
  echo $Mail->error; 
} 

?>