Consider following code

using System;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    public interface IServerNotifier
    {
        Task NotifyServer();
    }

    class Program
    {
        private static IServerNotifier Notifier;
        static void Main(string[] args)
        {
            Notifier.NotifyServer();
            Console.Write("Server notified.");
        }
    }
}

There are 2 problems: first - program may terminate before server is actually notified; second - what happens if server notification fails? Good chances that Task returned by NotifyServer() gets to GC and is going to throw an exception on finalizer thread. This is probably not the intended behavior. Most likely, the code above should look like

        static void Main(string[] args)
        {
            Notifier.NotifyServer().Wait();
            Console.Write("Server notified.");
        }

This R# plugin helps to spot such situations.