用socket发邮件 有个有关问题

用socket发邮件 有个问题
我看网上的用socket发邮件 
基本上都是吧内容让在
Subject :

XXXXXXX 就是这个地方了
.

但是我加了标签之后如div 
总是会被转义

那在内容中放张图片进去  直接接收不到了......郁闷
改怎么办了???
代码如下

	class aMail{
		public static $smtp_prot = 25;
		public static $debug = true;
		public static $crlf  = "\r\n";
		var $smtp_host;
		var $login_name;
		var $password;
		var $form;
		var $to;
		var $err;
		var $message;
		var $socket;
		function __construct($options=""){
			if($options == "" || !is_array($options)){
				return false;
			}
			foreach($options as $key=>$val){
				$this->$key = $val;
			}
		}

		function sendMail(){						 
			$this->socket = fsockopen($this->smtp_host,self::$smtp_prot);
			$socket = $this->socket;
			$crlf   = self::$crlf;
			stream_set_blocking($socket,true);
			$this->message = fgets($socket,512);	
			echo $this->message;
			if(!$this->print_messsage("/^220/","connect fail")){
				return false;
			}

			fputs($socket,"EHLO 127.0.0.1 ".$crlf);
			$this->message = fgets($socket, 512);				
			if(!$this->print_messsage("/^2/","EHLO fail")){
				return false;
			}
			
			fputs($socket,"AUTH LOGIN".$crlf);
			$this->message = fgets($socket, 512);				
			$this->print_messsage("/^2/","AUTH LOGIN fail");
			
			fputs($socket,base64_encode($this->login_name).$crlf);
			$this->message = fgets($socket, 512);				
			$this->print_messsage("/^2/","login_name fail");
			
			fputs($socket,base64_encode($this->password).$crlf);
			$this->message = fgets($socket, 512);				
			$this->print_messsage("/^2/","password fail");			

			fputs($socket,"MAIL FROM: <".$this->from.">".$crlf);
			$this->message = fgets($socket, 512);
			$this->print_messsage("/^2/","from fail");

			fputs($socket,"RCPT TO: <".$this->to.">".$crlf);
			$this->message = fgets($socket, 512);
			$this->print_messsage("/^334|^2/","to fail");
			
			fputs($socket,"DATA".$crlf);
			$this->message = fgets($socket, 512);
			$this->print_messsage("/^334|^2/","DATA fail");			

			$html = implode("",array(
						"To: ".$this->to.$crlf,
						"From: ".$this->from.$crlf,
						"Subject: ".$this->subject.$crlf.$crlf,
						$this->content.$crlf.".".$crlf,
					));

			fputs($socket,$html);
			$this->message = fgets($socket, 512);
			$this->print_messsage("/^2/","html fail");
			
			fputs($socket, "QUIT".$crlf);
			$this->message=fgets($socket,512);
			$this->print_messsage("/^2/","QUIT fail");
		}
		function print_messsage($reg="",$err=""){
			$message = $this->message;
			if(preg_match($reg,$message)<=0){
				$this->err = $err."___".$message."--------------";
				echo $err."___".$message."--------------<br>";
				return false;
			}
			if(self::$debug){
				echo $this->message."<br>";
			}
			return true;
		}
	}
	$mail_options = array(
					"smtp_host"=>"smtp.sina.com.cn",
					"login_name"=>"ycwtt0527",