用phpmailer类做发送邮件功能，提示500错误？

require("./class.phpmailer.php");$mail = new PHPMailer();$mail->IsSMTP();					// 启用SMTP$mail->Host = "smtp.sina.cn";			//SMTP服务器$mail->SMTPAuth = true;					//开启SMTP认证$mail->Username = "fgrhda";			// SMTP用户名$mail->Password = "123456";				// SMTP密码$mail->From = "fgrhda@163.com";			//发件人地址$mail->FromName = "Mailer";				//发件人$mail->AddAddress("97235694@qq.com", "Josh Adams");	//添加收件人//$mail->AddAddress("ellen@example.com");$mail->AddReplyTo("97235694@qq.com", "Information");	//回复地址$mail->WordWrap = 50;					//设置每行字符长度/** 附件设置$mail->AddAttachment("/var/tmp/file.tar.gz");		// 添加附件$mail->AddAttachment("/tmp/image.jpg", "new.jpg");	// 添加附件,并指定名称*/$mail->IsHTML(true);					// 是否HTML格式邮件$mail->Subject = "Here is the subject";			//邮件主题$mail->Body    = "This is the HTML message body <b>in bold!</b>";		//邮件内容$mail->AltBody = "This is the body in plain text for non-HTML mail clients";	//邮件正文不支持HTML的备用显示if(!$mail->Send()){   echo "Message could not be sent. <p>";   echo "Mailer Error: " . $mail->ErrorInfo;   exit;}echo "Message has been sent";