注册确认邮件

Question

[HttpPost]
        public ActionResult Register(User user)
        {

            if (ModelState.IsValid)
            {

 UserAPIController uApi = new UserAPIController(true);
                HttpResponseMessage response = uApi.Register(user, Request.QueryString["TeamId"]);
                if (response.StatusCode == System.Net.HttpStatusCode.Conflict)
                {
                    ModelState.AddModelError("", HttpContext.GetGlobalResourceObject("LanguageResource", "DuplicateEmailErrorMessage").ToString());
                    return View();
                }

                //Send Registration Email
                string EmailBodyStr = string.Empty;
                string EmailFrom = Helpers.CommonFunctions.GetApplicationSettingValue("SystemEmailId");
                string EmailSub = HttpContext.GetGlobalResourceObject("LanguageResource", "EmailTemplate_Reistration_Subject").ToString();
                string userName = user.FullName;
                if (string.IsNullOrEmpty(userName))
                {
                   userName = user.Email;
                }

                EmailBodyStr = HttpContext.GetGlobalResourceObject("LanguageResource", "EmailTemplate_Registration_TeamLeader_Body").ToString();
                EmailBodyStr = EmailBodyStr.Replace("[UserFullName]", userName);
                string email = HttpUtility.UrlEncode(Helpers.Encrypt.EncryptString(user.Email));
                EmailBodyStr = EmailBodyStr.Replace("[NavigationLink]", "<a href=" + "\"" + Helpers.CommonFunctions.GetApplicationSettingValue("ApplicationName") + "/User/Login?UserEmail=" + email + "\"" + ">click here</a>");
                if (EmailFrom != string.Empty)
                {
                    Helpers.Emailer.SendEmail(user.Email, EmailSub, EmailBodyStr, EmailFrom);
                }
                ModelState.AddModelError("", HttpContext.GetGlobalResourceObject("LanguageResource", "SuccessfullRegistrationMessage").ToString());
     }

            return View(user);
        }

我在mvc4中创建了一个注册表单，用户在注册后会收到确认电子邮件，但会发送两次相同的注册邮箱。以上是用于注册确认的代码。 请告诉我代码中的问题在哪里以及为什么它会两次触发相同的事件。