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Learn How to Disable EWS Throttling in Exchange Server Easily

Published By Nilesh Kumar
Debasish Pramanik
Approved By Debasish Pramanik
Published On September 19th, 2023
Reading Time 5 Minutes Reading
Category Exchange Server

While dealing with Exchange Server admins must have run into situations where they had to temporarily pause some functionality to set things right. One such scenario is when they have to disable EWS throttling in its entirety.  Exchange Web Services are part of Microsoft 365 and are designed to support and maintain the exchange server functionality in the cloud. 

Here throttling can be compared to a speed bump for your email system. Like a speed bump, it is there to slow down the resource demand from a single point. Although it is quite useful, sometimes admins might need to bypass this restraint. Therefore, in this detailed guide, we’ll dive into the ins and outs of EWS throttling, and walk you through the step-by-step process of disabling it.

Reasons to Disable EWS Throttling in Exchange Online

Whenever an organization decides to migrate its Exchange data one of the first steps it needs to do is disable EWS Throttling in Exchange Server.

This is done to remove the performance roadblocks that occur during a throttling operation. Other than that during migration other services are disabled anyway so the main task of throttling is no longer a priority. 

Another reason why throttling might be disabled is that some organizations have faced cyberattacks that took advantage of the throttling mechanism. Here nefarious entities used brute force tactics and gained access to the mail server, thus causing email compromise. 

Nonetheless, the main problem is that you can’t disable throttling completely as it is a critical component that prevents the overloading of resources. Moreover disabling the inbuilt mechanism is not only complicated but has several downsides such as stopping active sync among other apps\services.

However, users can still request a pause in the throttling service. To address the issue we have two different methods for the same let’s see them one by one.

Disable EWS Throttling Via Exchange Admin Center

Step 1. Log in to the Office 365 Admin page.

Step 2. Access the “Customize navigation” option in the feature pane.

Step 3. Hit the “Select All” option and then click “Save.”

Step 4. Choose “Need Help” or navigate to “Support,” and proceed with “New service requests.”

Step 5. Utilize the search field to find “EWS Throttling.” Pick “Increase EWS Throttling Policy” from the list and hit Enter.

Step 6. Click on “Run Tests.”

Step 7. Allow the diagnostics test to finish.

Step 8. Upon completion, opt for a duration of 30, 60, or 90 days for disabling the EWS Throttling Policy. Confirm by checking the acknowledgment checkbox and press “Update Settings.”

Step 9. The EWS throttling will now be disabled for the specified duration.

Step 10. The update to the Exchange Web Services (EWS) throttling policy has been initiated and will conclude within 15 minutes.

Step 11. After 15 minutes, rerun the test (Step 6) to confirm that the throttling has been successfully disabled.

Powershell Commands to Switch off EWS Throttling

To disable all throttling parameters for all mailboxes:

Step 1. Set up a connection in the Exchange Management Shell.

$UserCredential = Get-Credential
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri http://<ServerFQDN>/PowerShell/ -Authentication UserAdmin -Credential $UserCredential

Step 2. Execute the following set of commands next.


Step 3. Then, type in the following code and press Enter on your keyboard.

MigrationPolicy -RCAMaxConcurrency Unlimited
-EWSMaxConcurrency Unlimited -EWSMaxSubscriptions Unlimited
-CPAMaxConcurrency Unlimited -EwsCutoffBalance Unlimited
-EwsMaxBurst Unlimited -EwsRechargeRate Unlimited

Step 4. Put the following commands to confirm the settings and disable Disable EWS throttling.  

| Set-Mailbox -ThrottlingPolicy MigrationPolicy

Note: Powershell commands can result in unforeseen changes therefore users should only use these if they have a decent experience of working with Powershell.

Best Option For Data Migration After Disabling Throttling

Once EWS throttling is disabled users must act fast or they will lose this golden opportunity to move their data. One way to speed up the data transfer is to use the Exchange to Exchange Migration Tool. This utility is specifically designed to make migration as simple as possible. Various exchange migration scenarios can be completed via this tool such as:

Moreover, with the intricate user-friendly interface even nontechnical personnel can attempt and complete the data migration with ease.

Download Now Purchase Now

Here is a list of 5 quick steps after which the data will be shifted to the desired location.

Step 1. Launch the tool and select Exchange as both Source and Destination.

Select Source and Destination as Exchange

Step 2. Mark the Workload boxes and Apply the date filter if required.

Select Workload and Apply Date Filters

Step 3. Validate both source and target information one by one.

Select Exchange Server Version as 2016

Step 4. Prepare a user mapping in one of 3 ways (Fetch, Import, Download).

Add Users

Step 5. Preview users, validate, and hit Start migration.

Start Migration


In this article, we learned the methods to disable EWS throttling in Exchange Server. By following the steps outlined in this guide, administrators can make informed decisions on when to pause throttling. Moreover, we saw why this practice is not recommended and how it is only paused for a limited time period. In the end, we completed our discussion by getting to know the best available tool for data transfer while throttling is no longer active.


By Nilesh Kumar

As a Chief Technical Writer, I know the technical issues faced by home and professional users. So, I decided to share all my knowledge via this blog. I love to help you with challenges while dealing with technical jargon.