New-ThrottlingPolicy SuThrottlingPolicy -EWSMaxConcurrency $null -EWSMaxSubscriptions $null
Set-ThrottlingPolicyAssociation -Identity exsu -ThrottlingPolicy SuThrottlingPolicy
For the inquiring minds, the following are set in Exchange 2010, but NOT used in Exchange 2013:
|Throttling policy parameter
|Indicates that there are more concurrent requests against the server than are allowed by a user's policy.
|Indicates that a user's throttling policy maximum subscription count has been exceeded.
|Indicates that a search operation call has exceeded the total number of items that can be returned.
|Occurs when the server is busy. The BackOffMilliseconds value returned with ErrorServerBusy errors indicates to the client the amount of time it should wait until it should resubmit the request that caused the response that returned this error code.
Or, the HTTP status codes that are returned by throttling errors:
|HTTP status code
|Indicates that EWS requests are queuing with IIS. The client should delay sending additional requests until a later time.
|Indicates an internal server error with the ErrorServerBusy error code. This indicates that the client should delay sending additional requests until a later time. The response may contain a back off hint called BackOffMilliseconds. If present, the value of BackOffMilliseconds should be used as the duration until the client resubmits a request.
|Contains an EWS schema-based error response with an ErrorInternalServerError error code. An inner ErrorServerBusy error code may be present. This indicates that the client should delay sending additional requests until a later time.