c#发送邮件

            System.Net.Mail.SmtpClient client = new System.Net.Mail.SmtpClient();
            client.Host = "smtp.qq.com"; //SMTP服务器
            client.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
            client.Port = 25;
            client.UseDefaultCredentials = true;
            client.Credentials = new System.Net.NetworkCredential("1000", "******"); //SMTP服务器需要用户名和密码作认证(这里填写qq号和独立密码)



            //这里假定你已经拥有了一个qq邮箱的账户，qq号为1000，密码为******(qq邮箱需要开启SMTP服务，开启时会需要设置独立密码这里的密码采用的是独立密码)
           
            System.Net.Mail.MailMessage Message = new System.Net.Mail.MailMessage(); //创建一个电子邮件类
            Message.From = new System.Net.Mail.MailAddress("1000@qq.com"); //发件人Email
            Message.To.Add("123@qq.com"); //收件人Email
            Message.Subject = "邮件标题";
            Message.Body = "邮件内容";
            // string file = Server.MapPath("data.txt"); 
            // Message.Attachments.Add(new Attachment(file)); //添加附件
            Message.SubjectEncoding = System.Text.Encoding.UTF8;
            Message.BodyEncoding = System.Text.Encoding.UTF8;
            Message.Priority = System.Net.Mail.MailPriority.High;
            Message.IsBodyHtml = false;
            try
            {
                client.Send(Message);
            }
            catch (Exception e)
            {
                Response.Write(e.Message.ToString());
            }
            finally
            {
                Message.Dispose();
                client.Dispose();
            }