How to Disable Throttling in Microsoft Exchange Server 2013 and Newer

Microsoft Exchange Server 2013 message throttling policies set bandwidth limits and restrict the number of processed messages. Throttling is enabled by default on Microsoft Exchange 2013. In order to disable throttling, you must create an appropriate policy and assign it to the service account as documented in the Microsoft Technet article Set Throttling Policy.

Step 1. Create a Service New Account

If you have not already done so, create a new service account using the steps in the article Creating an Email Service Account for Microsoft Exchange Server.

Note the name of the Service account you created. You will need it below in Steps 2 and 3.

Step 2. Assign Permissions

Use the following steps to assign permissions to the account. Replace CUDASVC with the account you created in the previous step.

1. Log into the Exchange Server as the administrator, and open the Exchange Management Shell.
2. At the command prompt, type the following command:
   New-ManagementRoleAssignment -Name:BarracudaMessageArchiver -Role:ApplicationImpersonation -User:CUDASVC

Step 3. Disable Throttling Policy Enforcement

Use the following steps to disable throttling policy enforcement on the new account, replacing NewUserPolicy with the name of the throttling policy:

1. Log into the Exchange Server as the administrator, and open the Exchange Management Shell.
2. At the command prompt, type the following command to create a new throttling policy:
   New-ThrottlingPolicy <NewUserPolicy>
3. Press Enter. Type the following command to set the throttling policy:
   Set-ThrottlingPolicy <NewUserPolicy> -RCAMaxConcurrency Unlimited -EWSMaxConcurrency Unlimited -EWSMaxSubscriptions Unlimited -CPAMaxConcurrency Unlimited -EwsCutoffBalance Unlimited -EwsMaxBurst Unlimited -EwsRechargeRate Unlimited
4. Press Enter. Type the following command to disable policy enforcement:
   Set-Mailbox "CUDASVC" -ThrottlingPolicy <NewUserPolicy>
5. Press Enter.