Some errors can disrupt the functioning of the Email Notification Service (ENS). The scenarios during which these errors are seen and the workaround to overcome these errors are listed in this section.

When the users’ accounts are on different Exchange servers and the Exchange Web Service (EWS) urls are different, ENS server is unable to subscribe all the users successfully

When the ENS subscribes the users to Exchange and if the mailboxes are present on another Exchange server, an error is generated.

2017/04/10 16:19:29.032        DCAIRWENSP01   4f99428c-01d8-4882-95b7-78b6f8a2ea70
                  [0000000-0000000]   (36)       Warn AW.Mail.Notification.BusinessImpl.ExchangeStreamingNotificationSubscriber._SubscribeUsers
                  Subscription Error MailBox {MailBox Address}, Error Microsoft.Exchange.WebServices.Data.ServiceResponseException:
                  One or more subscriptions in the request reside on another Client Access server. GetStreamingEvents
                  won't proxy in the event of a batch request.

To restore the notification functionality of the ENS server, perform the following steps:

  1. Navigate to the ENS installation folder and open the AW.Mail.Notification.Service.Config file.
  2. Find the 'autoDiscoverEnabled' and 'autoDiscoverUrl' parameters.
  3. Set autoDiscoverEnabled parameter value to 'true' and provide the autoDiscoverUrl in the following format, https://autodiscover.domainname/Autodiscover/Autodiscover.svc


You must set the autoDiscoverEnabled to 'true' and provide the autoDiscoverUrl regardless of whether you are using the streaming model or push model.

If all the users’ have the same EWS URL, then set the autoDiscoverEnabled parameter value to 'false'.

When there are multiple Exchange server versions but all the Exchange servers have the same domain, ENS server is unable to complete all the subscriptions correctly

ENS server functionality is interrupted when multiple Exchange server versions are configured with the same domain. You can either create separate domains for different Exchange server versions or install separate instances of ENS that are specific to each domain.