public string UpdateAppointmentInOutlook(AppointmentEntity appointmentEntity)
        {
            Trace.TraceInformation("UpdateAppointmentInOutlook");

            if (!InitializeHelpers())
            {
                return("Initialize helpers fail");
            }
            appointmentEntity.OutlookId = crmHelper.GetOutlookId(appointmentEntity);
            exchangeHelper.UpdateOutlookAppointment(appointmentEntity);
            //crmHelper.UpdateCrmAppointment(appointmentEntity);
            return("Update appointment success");
        }