Hello,

I've configured an application to use a specific service account to access my users' mailboxes. I've created and associated a throttling policy with this service account (no limit, null values).

In reviewing the event logs, I come across an error that seems to suggest the unlimited throttling policy is not being honored.

Microsoft.Exchange.Data.Directory.SystemConfiguration.OverBudgetException: This operation exceeds the throttling budget for policy part 'CAS', budget type: 'EWS'. Suggested backoff time 27227 ms. at Microsoft.Exchange.Data.Directory.Budget.CheckOverBudget(CostType costType) at Microsoft.Exchange.Services.Core.PushSubscription.BuildNotification()

Does anyone know what (specifically) 'policy part 'CAS', budget type: 'EWS'.' is referring to? 

Hi Joseph,

I hope you have restarted the RPC (and probably WWW) service after setting up the unrestricted throttling policy.

I'd suggest you also check the EWS Logs on the CAS server this will give you more details into what if any operations are putting you over budget what users, when etc. Also you might want to check your patch/sp level there was an issue where Fallback policies can be used see https://support.microsoft.com/en-gb/kb/2668900

Cheers
Glen

Thank you, will review this and update the thread.