Exchange 2010 has a much lower throttling limit than previous versions of Exchange. You may find it necessary to disable throttling on a specific account for administrative purposes.

To do this we will create a new throttling policy, set properties on it, and set the policy on the mailbox. The example below creates a policy and assigns it to the UberMail user.

New-ThrottlingPolicy UberMailPolicy

Set-ThrottlingPolicy UberMailPolicy -RCAMaxConcurrency $null -RCAPercentTimeInAD $null -RCAPercentTimeInCAS $null -RCAPercentTimeInMailboxRPC $null -EWSMaxConcurrency $null -EWSPercentTimeInAD $null -EWSPercentTimeInCAS $null -EWSPercentTimeInMailboxRPC $null -EWSMaxSubscriptions $null -EWSFastSearchTimeoutInSeconds $null -EWSFindCountLimit $null -CPAMaxConcurrency $null -CPAPercentTimeInCAS $null -CPAPercentTimeInMailboxRPC $null -CPUStartPercent $null

Set-Mailbox "UberMail" -ThrottlingPolicy UberMailPolicy