using System.Net;

        using System.Net.Mail;

        using System.Text;

        protected void button1_Click(object sender, EventArgs e)

        {

            MailMessage msg = new MailMessage();

            msg.To.Add("收件人地址@qq.com");

            msg.CC.Add("抄送人地址@qq.com");

            msg.From = new MailAddress("发件人邮箱@qq.com", "名称");

            msg.Subject = "邮件标题";

            //标题格式为UTF8

            msg.SubjectEncoding = Encoding.UTF8;

            msg.Body = "邮件内容";

            //内容格式为UTF8

            msg.BodyEncoding = Encoding.UTF8;

            SmtpClient client = new SmtpClient();

            //SMTP服务器地址

            client.Host = "smtp.qq.com";

            //SMTP端口，QQ邮箱填写587

            client.Port = ;

            //启用SSL加密

            client.EnableSsl = true;

            client.Credentials = new NetworkCredential("发件人邮箱账号@qq.com", "密码或者授权码");

            //发送邮件

            try

            {

                client.Send(msg);

            }

            catch (SmtpException ex)

            {

            }

            finally

            {

                client.Dispose();

                msg.Dispose();

            }

        }