How to disable Exchange 2010 / 2013 / 2016 Throttling

Last update:
Created :
Written by Thomas Speekenbrink

Overview:

Sometimes you will need to disable throttling for the syncuser, as the Exchange server is blocking connections to the Exchange Server made by the SyncUser.

Depending on the Synchronizer usage, it might happen that the Synchronizer will need to make many connections which the Exchange server, which is why Exchange decides to block new connections (based on the active Throttling policy).

This article applies to:

  • Exchange Online Synchronizer (EWS)
  • Nebula Synchronizer

How to:

Exchange 2010

To disable the EWS throttling for Exchange 2010 for a user called SyncUser, you should use the following Exchange PowerShell command:

  • New-ThrottlingPolicy IBSyncPolicy
  • Set-ThrottlingPolicy IBSyncPolicy -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 "SyncUser" -ThrottlingPolicy IBSyncPolicy

Exchange 2013 / 2016

To disable the EWS throttling for Exchange 2013 / 2016 for a user called SyncUser, you should use the following Exchange PowerShell command:

  • New-ThrottlingPolicy IBSyncPolicy
  • Set-ThrottlingPolicy IBSyncPolicy -RCAMaxConcurrency Unlimited -EWSMaxConcurrency Unlimited -EWSMaxSubscriptions Unlimited -CPAMaxConcurrency Unlimited -EwsCutoffBalance Unlimited -EwsMaxBurst Unlimited -EwsRechargeRate Unlimited
  • Set-Mailbox "SyncUSer" -ThrottlingPolicy IBSyncPolicy

Extra:

It might happen that it is not possible to disable the throttling policy completely, then you can also set a highter EWS Max concurrency for the exchange users. We recommend that you toggle between 100 or 250, if you get in the eventlog the message "... Exchange server down" then set the amount higher (maximum value 250).

  • Get-ThrottlingPolicy | where-object {$_.IsDefault -eq $true} | set-throttlingpolicy -EWSMaxConcurrency 250

Because every situation is different, it's a bit of trial & error which value works best.