Removing MAPI session throttling for Folder Sync on Exchange 2013

Last published : Apr 17, 2026
You can use Exchange Management Shell commands to create a new throttling policy which sets no throttling, and then to set the Folder Sync service account to use the new policy.
To remove MAPI session throttling for Folder Sync on Exchange 2013
  1. Start the Exchange Management Shell.
  2. Enter the following command to create the new throttling policy:
New-ThrottlingPolicy ATFSPolicy -IsServiceAccount:$true -RcaMaxConcurrency Unlimited -RcaMaxBurst Unlimited -RcaRechargeRate Unlimited -RcaCutOffBalance Unlimited -DomainController DC_Fully_Qualified_HostName
where DC_Fully_Qualified_HostName is the fully qualified host name of the domain controller
  1. Enter the following command to assign the new policy to the Folder Sync service account:
Set-Mailbox "Service_Account" -ThrottlingPolicy ATFSPolicy
where Service_Account is the name of the Folder Sync service account.
More Information
Configuring sufficient concurrent MAPI sessions for Folder Sync
Steps to set up Folder Sync