public static void SendMailUse()

        {

            string host = "smtp.lotusest.com";// 邮件服务器smtp.163.com表示网易邮箱服务器

            string userName = "s********t.com";// 发送端账号

            string password = "";// 发送端密码(这个客户端重置后的密码)

            SmtpClient client = new SmtpClient();

            client.DeliveryMethod = SmtpDeliveryMethod.Network;//指定电子邮件发送方式

            client.Port = ;//gmail的端口号

            client.Host = host;//邮件服务器

            client.UseDefaultCredentials = true;

            client.Credentials = new System.Net.NetworkCredential(userName, password);//用户名、密码

            //////////////////////////////////////

            string strfrom = userName;

            string strto = "2694215660@qq.com";

            string strcc = "2694215660@qq.com";//抄送

            string subject = "这是测试邮件标题5";//邮件的主题

            string body = "测试邮件内容5";//发送的邮件正文  

            System.Net.Mail.MailMessage msg = new System.Net.Mail.MailMessage();

            msg.From = new MailAddress(strfrom, "xyf");

            msg.To.Add(strto);

            msg.CC.Add(strcc);

            msg.Subject = subject;//邮件标题

            msg.Body = body;//邮件内容

            msg.BodyEncoding = System.Text.Encoding.UTF8;//邮件内容编码

            msg.IsBodyHtml = true;//是否是HTML邮件

            msg.Priority = MailPriority.High;//邮件优先级   

            try

            {

                client.Send(msg);

                Console.WriteLine("发送成功");

            }

            catch (System.Net.Mail.SmtpException ex)

            {

                Console.WriteLine(ex.Message, "发送邮件出错");

            }

        }