title: Proxy Authentication Required (Forefront TMG requires authorization to fulfill the request. Access to the Web Proxy filter is denied.)
body: <p>When I was trying to post messages to Twitter, the above error coming. How to get rid of that error? </p>
  
  <p>The stacktrace is the following:</p>
  
  <blockquote>
    <p>Exception = {"The remote server returned an error: (407) Proxy Authentication Required."} ExceptionStatus = ProtocolError</p>
  </blockquote>
  
  <p>Code:</p>
  
  <pre><code>private string GetOAuthUrl()
  {
      IFluentTwitter twitter;
  
      //Override the callback url if one was entered
      if (CallbackUrl != null &amp;&amp; CallbackUrl.Trim().Length &gt; 0)
      {
          twitter = FluentTwitter.CreateRequest().Configuration.UseHttps().Authentication.GetRequestToken(ConsumerKey, ConsumerSecret, CallbackUrl);
      }
      else
      {
          twitter = FluentTwitter.CreateRequest().Configuration.UseHttps().Authentication.GetRequestToken(ConsumerKey, ConsumerSecret);
      }
  
      var response = twitter.Request();
      UnauthorizedToken UnauthorizedToken = response.AsToken();
  
      string AuthorizationUrl = FluentTwitter.CreateRequest().Authentication.GetAuthorizationUrl(UnauthorizedToken.Token);
      return AuthorizationUrl;
  }
  </code></pre>