Exchange 2007 introduced a feature called RPC Client Throttling to allow administrators to manage end-user performance by preventing client applications, such as Outlook for example, from sending too many Remote Procedure Call [RPC] requests per second to Exchange, causing the server to suffer in terms of performance. When Exchange determines that a client is having a negative effect on the server, it will send a “back-off” request to the client telling it to delay sending any additional requests for a specified time (maximum of 2000 milliseconds) in order to reduce the performance effect on the server.
In Exchange 2010, Client Throttling has been much improved, monitoring and controlling much more than just RPC requests. Its purpose is still to ensure that users are not intentionally or unintentionally straining Exchange and that users share resources proportionally.
There is also Message Throttling in Exchange that restricts the number of messages and the number of connections that can be processed by an Exchange Transport server. In this article we will be talking only about Client Throttling.
Exchange 2010 server supports client request throttling. This can limit the performance of
GAMME migrations when performing a large number of user migrations. To mitigate this, you
can configure a specific policy to the GAMME Administrator account that exempts it from
Follow these steps to create and apply a custom throttling policy.
On the Microsoft Exchange Server, click Start > Microsoft Exchange Server 2010 > Exchange
In the shell, enter the following:
New-ThrottlingPolicy GAMME -RCAMaxConcurrency $null -RCAPercentTimeInAD $null –RCAPercentTimeInCAS $null -RCAPercentTimeInMailboxRPC $null
Set-Mailbox “GAMME_Admin” -ThrottlingPolicy GAMME