ASP.NET发送邮件程序

Question

我的代码：            try
            {
                MailMessage msg = new MailMessage();
                MailAddress address = new MailAddress("发送的邮箱");
                MailAddressCollection collection = new MailAddressCollection();
                collection.Add("接收的邮箱");
                msg.From = address;
                msg.To.Add(collection[0].Address.ToString());
                msg.IsBodyHtml = true;
                msg.Body = "这是我的测试邮件";
                string hostName = Dns.GetHostName();
                IPAddress[] ipAddress = Dns.GetHostAddresses(hostName);
                string ip = ipAddress[0].ToString();
                SmtpClient client = new SmtpClient();
                client.Host = "qq.smtp.com";
                client.Send(msg);
            }
            catch (Exception ex)
            {
                Response.Write("<script language='javascript'>alert('" + ex.Message + "')</script>");
            }

但是，始终提示发送失败。在这里，我只是写了代码，没有在WEB.CONFIG里面进行配置，也没有设置SMTP服务，请问，代码有问题吗？请给出正确的提示，谢谢！