.net 发邮件

 MailAddress from = new MailAddress("xx@qq.com", "alexyuan");
                MailAddress to = new MailAddress("xx@qq.com", "alex");
                System.Net.Mail.MailMessage mymail = new System.Net.Mail.MailMessage(from, to);
                mymail.Subject = "hello";
                mymail.Body = "hello Mr S";
                SmtpClient client = new SmtpClient("smtp.qq.com");
                client.UseDefaultCredentials = true;
                client.Credentials = new NetworkCredential("xx@qq.com", "xx");
                client.DeliveryMethod = SmtpDeliveryMethod.Network;
                mymail.IsBodyHtml = true;
                client.Send(mymail);