title: IIdentityMessageService not found
body: <p>I am creating a web application using the asp.net MVC5 with Visual Studio 2013. I installed the sendgrid API into my solution, and created a class that implements the interface <code>IIdentityMessageService</code> (actually I am following a tutorial). the problem is, VS keeps saying that the interface could not be found or I am missing an assembly reference. I double checked, I have all the Includes that I need and all the assembly references. I even went to the microsoft site and checked if I was using the correct one. Here's the code:</p>
  
  <pre><code>using SendGrid;
  using System;
  using System.Collections.Generic;
  using System.Configuration;
  using System.Diagnostics;
  using System.Linq;
  using System.Net;
  using System.Threading.Tasks;
  using System.Web;
  using Microsoft.AspNet.Identity;
  
  
  namespace ESW.Models
  {
      public class EmailService : IIdentityMessageService
      {
          public async Task SendAsync(IdentityMessage message)
          {
              await configSendGridasync(message);
          }
  
          // Use NuGet to install SendGrid (Basic C# client lib) 
          private async Task configSendGridasync(IdentityMessage message)
          {
              var myMessage = new SendGridMessage();
              myMessage.AddTo(message.Destination);
              myMessage.From = new System.Net.Mail.MailAddress(
                                  "Joe@contoso.com", "Joe S.");
              myMessage.Subject = message.Subject;
              myMessage.Text = message.Body;
              myMessage.Html = message.Body;
  
              var credentials = new NetworkCredential(
                         ConfigurationManager.AppSettings["mailAccount"],
                         ConfigurationManager.AppSettings["mailPassword"]
                         );
  
              // Create a Web transport for sending email.
              var transportWeb = new Web(credentials);
  
              // Send the email.
              if (transportWeb != null)
              {
                  await transportWeb.DeliverAsync(myMessage);
              }
              else
              {
                  Trace.TraceError("Failed to create Web transport.");
                  await Task.FromResult(0);
              }
          }
      }
  }
  </code></pre>
  
  <p>EDIT: <a href="http://msdn.microsoft.com/en-us/library/microsoft.aspnet.identity.iidentitymessageservice(v=vs.108).aspx" rel="nofollow">http://msdn.microsoft.com/en-us/library/microsoft.aspnet.identity.iidentitymessageservice(v=vs.108).aspx</a></p>
  
  <p>That is the page I used to verify the assembly reference.</p>