using System.Net.Mail;//邮件发送需引用 
public ActionResult bindStep3(ModelCompany c)
    {
      .........
      ..........
      ...........
      MailAddress MessageFrom = new MailAddress("xxxxx@qq.com"); //发件人邮箱地址 
      string MessageTo = company.COMPANY_EMAIL; //收件人邮箱地址 
      string MessageSubject = "激活验证"; //邮件主题 
      string MessageBody = "请进行邮箱验证来完成您注册的最后一步,点击下面的链接激活您的帐号：<br><a target='_blank' rel='nofollow' style='color: #0041D3; text-decoration: underline' href=''>激活</a>"; //邮件内容 （一般是一个网址链接，生成随机数加验证id参数，点击去网站验证。）
 
    if (SendMail(MessageFrom, MessageTo, MessageSubject, MessageBody))
    {
      Response.Write("<script type='text/javascript'>alert('发送邮件失败');</script>");
    }
    else
    {
      Response.Write("<script type='text/javascript'>alert('发送邮件失败');</script>");
    }
      TempData["CompanyBind3"] = company;
      return View("bindStep3");
    }

    public bool SendMail(MailAddress MessageFrom,string MessageTo,string MessageSubject,string MessageBody)  //发送验证邮件
    {
      MailMessage message = new MailMessage();
      message.To.Add(MessageTo);
      message.From = MessageFrom;
      message.Subject = MessageSubject;
      message.SubjectEncoding = System.Text.Encoding.UTF8;
      message.Body = MessageBody;
      message.BodyEncoding = System.Text.Encoding.UTF8;
      message.IsBodyHtml = true; //是否为html格式 
      message.Priority = MailPriority.High; //发送邮件的优先等级 
      SmtpClient sc = new SmtpClient();
      sc.EnableSsl = true;//是否SSL加密
      sc.Host = "smtp.qq.com"; //指定发送邮件的服务器地址或IP 
      sc.Port = 587; //指定发送邮件端口 
      sc.Credentials = new System.Net.NetworkCredential("xxxxx@qq.com", "xxxxx"); //指定登录服务器的用户名和密码(注意：这里的密码是开通上面的pop3/smtp服务提供给你的授权密码，不是你的qq密码)

      try
      {
        sc.Send(message); //发送邮件 
      }
      catch(Exception e)
      {
        Response.Write(e.Message);
        return false;
      }
      return true;
      
    }