using System;

using Newtonsoft.Json;

​

public class Program

{

    public static void Main()

    {

        string json = @"{'Email': 'james@example.com'}";

        var dyn = JsonConvert.DeserializeObject<dynamic>(json);

        if (Object.ReferenceEquals(null, dyn["Email"]))

        {

            Console.WriteLine("no email");

        }

        else

        {

            Console.WriteLine(dyn["Email"].ToString());

        }

    }

}