Hangfire - wysyłka email w tle

BaseMailer.cs

public class BaseMailer
{
    protected void Send(Email email)
    {
        var mailerName = GetType().Name.Replace("Mailer", string.Empty);

        var viewsPath = Path.GetFullPath(string.Format(HostingEnvironment.MapPath(@"~/Views/Emails/{0}"), mailerName));
        var engines = new ViewEngineCollectionWithoutResolver();
        engines.Add(new FileSystemRazorViewEngine(viewsPath));

        var emailService = new EmailService(engines);

        emailService.Send(email);
    }

    private class ViewEngineCollectionWithoutResolver : ViewEngineCollection
    {
        public ViewEngineCollectionWithoutResolver()
        {
            var resolverField = typeof(ViewEngineCollection).GetField("_dependencyResolver",
                BindingFlags.NonPublic | BindingFlags.Instance);

            var resolver = new EmptyResolver();
            resolverField.SetValue(this, resolver);
        }

        private class EmptyResolver : IDependencyResolver
        {
            public object GetService(Type serviceType)
            {
                return null;
            }

            public IEnumerable<object> GetServices(Type serviceType)
            {
                return Enumerable.Empty<object>();
            }
        }
    }
}

Startup.cs

public class Startup
{
    public void Configuration(IAppBuilder app)
    {
        GlobalConfiguration.Configuration
            .UseSqlServerStorage("DefaultConnection");

        app.UseHangfireDashboard();
        app.UseHangfireServer();
    }
}

UserLogic.cs

public void Add(User user)
{
    if (user == null)
    {
        throw new ArgumentNullException("user");
    }

    //walidacja danych

    //zapis danych w bazie

    //wysyłka maila
    //UserMailer.SendRegisterEmail(user);
    BackgroundJob.Enqueue(() => UserMailer.SendRegisterEmail(user));
}

web.config

<connectionStrings>
  <add name="DefaultConnection" connectionString="Server=localhost\sqlexpress;Database=PostalAndHangfire;Trusted_Connection=True;" providerName="System.Data.SqlClient" />
</connectionStrings>