关于smtp发邮件，谁能帮忙看看 503 Error: need EHLO and AUTH first

if(!$fp=fsockopen($this->smtp['host'],$this->smtp['port'],$errno,$errstr)){

			$this->message[]="连接邮件服务器失败，请检查：\r\n1、服务器地址和端口是否设置正确！\r\n2、网络是否通畅！";

			return false;

		}

		if(strncmp(fgets($fp,512),'220',3)!=0){

			$this->message[]="连接邮件服务器失败，请检查：\r\n1、服务器地址和端口是否设置正确！\r\n2、网络是否通畅！";

			return false;

		}

		if($this->smtp['auth']){

			fwrite($fp,"EHLO ".$this->smtp['posthost']."\r\n");

			while($rt=strtolower(fgets($fp,512))){

				if(strpos($rt,"-")!==3 || empty($rt)){

					break;

				}elseif(strpos($rt,"2")!==0){

					$this->message="与服务器招呼握手时错误";

					return false;

				}

			}

			fwrite($fp, "AUTH LOGIN\r\n");

			if(strncmp(fgets($fp,512),'334',3)!=0){

				$this->message="提示服务器要登陆验证时错误";

				return false;

			}



			fwrite($fp, base64_encode($this->smtp['user'])."\r\n");

			if(strncmp(fgets($fp,512),'334',3)!=0){

				$this->message="SMTP AUTH LOGIN 验证 用户名 错误！";

				return false;

			}

			fwrite($fp, base64_encode($this->smtp['pass'])."\r\n");

			if(strncmp(fgets($fp,512),'235',3)!=0){

				$this->message="SMTP AUTH LOGIN 验证 密码 错误！";

				return false;

			}

		} else{

			fwrite($fp, "HELO ".$this->smtp['posthost']."\r\n");

		}

		$from = $this->smtp['from'];

		$from = preg_replace("/.*\<(.+?)\>.*/", "\\1", $from);

		fwrite($fp, "MAIL FROM: <$from>\r\n");

		if(strncmp(fgets($fp,512),'250',3)!=0){

			$this->message="发信人地址错误！";

			return false;

		}

		fwrite($fp, "RCPT TO: <$toemail>\r\n");

		if(strncmp(fgets($fp,512),'250',3)!=0){

			$this->message="收信人地址错误！";

			return false;

		}

		fwrite($fp, "DATA\r\n");

		if(strncmp(fgets($fp,512),'354',3)!=0){

			$this->message="邮件数据发送失败！";

			return false;

		}

		$msg  = "Date: ".date("r")."\r\n";

		$msg .= "Subject: $send_subject\r\n";

		$msg .= "$additional\r\n";

		$msg .= "$send_message\r\n.\r\n";

		fwrite($fp, $msg);

		$lastmessage = fgets($fp, 512);

		if(substr($lastmessage, 0, 3) != 250){

			$this->message="连接邮件服务器失败，请检查：\r\n1、服务器地址和端口是否设置正确！\r\n2、网络是否通畅！";

			return false;

		}

		fwrite($fp, "QUIT\r\n");

		fclose($fp);

		return true;