StreamingNotifications not working with Office 365 / Exchange Online

Question

I have developed a small console application to test EWS StreamingSubscriptions / Notifications. In the past we used Push Notifications but ,in theory, when using StreamingNotifications I should be able to avoid creating a listener http endpoint and all the trouble with it (firewall, etc.).

So, from my local machine; I'm doing this:

static void Main(string[] args)
    {
        if (String.IsNullOrEmpty(ConfigurationManager.AppSettings["PrimaryLabUserId"]))
        {
            throw new ArgumentNullException("Please provide a value for PrimaryLabUserId in app.config");
        }
        _primaryLabUserId = ConfigurationManager.AppSettings["PrimaryLabUserId"];

        string ServiceAccountName = ConfigurationManager.AppSettings["ExchangeServiceAccountName"];
        string ServiceAccountPassword = ConfigurationManager.AppSettings["ExchangeServiceAccountPassword"];


        _service = new ExchangeService(ExchangeVersion.Exchange2010_SP2);
        _service.Credentials = new WebCredentials(ServiceAccountName, ServiceAccountPassword);
        _service.AutodiscoverUrl(_primaryLabUserId, (x) => true);
        _ewsUrl = _service.Url.AbsoluteUri;

        var _connection =  new StreamingSubscriptionConnection(_service, 30);

        var sub = SubscribeForStreamingNotifications();

        _connection.AddSubscription(sub);

        _connection.OnDisconnect +=
            new StreamingSubscriptionConnection.SubscriptionErrorDelegate(OnDisconnect);

        // set up subscriptions here.
        _connection.OnNotificationEvent +=
                    new StreamingSubscriptionConnection.NotificationEventDelegate(OnNewMail);

        _connection.Open();
        Console.WriteLine("Listening streaming...");
        Console.ReadLine();


    }

public static StreamingSubscription SubscribeForStreamingNotifications()
    {

                   var folderIds = new List<FolderId>()
        {
            WellKnownFolderName.Inbox,
            WellKnownFolderName.Calendar
        };

                    var eventTypes = new List<EventType>();
        eventTypes.Add(EventType.NewMail);
        eventTypes.Add(EventType.Deleted);
        eventTypes.Add(EventType.Moved);
        eventTypes.Add(EventType.Created);
        eventTypes.Add(EventType.Modified);

        return _service.SubscribeToStreamingNotifications(folderIds, eventTypes.ToArray());
    }

private static void OnNewMail(object sender, NotificationEventArgs args)
    {
        var test = args;
        Console.WriteLine("Incoming");
    }

The Subscription initializes OK, but when I send a new mail to the LabUser nothing happens. The Notification Event never fires. I tried the same with pushnotifications and it was working (on another server with a public http endpoint for exchange to call back). I was wondering if this might have anything to do with my local machine.

Answer 1

How very stupid of me. I forgot to impersonate. Since I'm calling into EWS with a service account it is of course listening on the mailbox of that account unless you specify:

 _service.ImpersonatedUserId = new ImpersonatedUserId(ConnectingIdType.SmtpAddress, _primaryLabUserId);