Sending POST Request to external site not working ASP.NET

I am trying to send an XML request via a HTTPWebRequest however I keep getting a message that the site could not be reached.

However if I turn on Fiddler the request goes through successfully, does anyone know why this might be happening?

This is the code that I am using to send through a request, the request is going to this address http://ift.tt/1BwPMH7

public static string SendRequest(string requestContent, string requestContentType, string requestUrl)
    {
        try
        {
            var request = (HttpWebRequest)WebRequest.Create(requestUrl);
            byte[] bytes;

            bytes = System.Text.Encoding.UTF8.GetBytes(requestContent);

            request.ContentType = requestContentType + "; encoding='utf-8'";
            request.ContentLength = bytes.Length;
            request.Method = "POST";
            //request.Timeout = 5000;

            //ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;

            using (var requestStream = request.GetRequestStream())
            {
                requestStream.Write(bytes, 0, requestContent.Length);
            }

            using (var response = (HttpWebResponse)request.GetResponse())
            {
                using (var responseStream = response.GetResponseStream())
                {
                    return new StreamReader(responseStream).ReadToEnd();
                }
            }
        }
        catch (Exception ex)
        {
            return ex.ToString();
        }
    }