What is throttling?



Throttling is a security mechanism that keeps a server healthy and responsive. It is called "throttling" because it limits the work load coming through the server by regulating network traffic and minimizing bandwidth congestion. As a result, you may experience slow Internet and performance speeds, which in turn can impact the speed of your backup or restore.

Throttling is a general condition that all Microsoft Office 365 applications have to deal with and it is not something that can be affected or changed through configuration or regular troubleshooting.

Microsoft offers only a limited amount of bandwidth to each of their Office 365 or OneDrive customers and applications installed by those customers cannot go beyond those limits. Allocation of bandwidth is based on the number of licensed users on the platform.


Can I do anything about it?

If you experience slow performance in Keepit, please ensure that you are not running other data intensive solutions against your Microsoft Office 365 tenant, such as synchronization or secondary backup services. 

If this is not the case, then you can have Microsoft temporarily raise your throttling limits on Exchange.

You can do this either by disabling EWS throttling from the Office 365 admin page or by sending a request to Microsoft support.


  • Disable EWS throttling in Office 365


1. Log in to the Office 365 admin page with your Global admin credentials.
2. Open the Admin app.

3. In the left navigation pain, select Support and then New service requests.

4. In the search field, search for throttling. Select Increase EWS Throttling Policy from the list and press Enter.


5. Select Run Tests. Diagnostic tests will run.


6. Select the duration in days. The options are 30 days, 60 days, and 90 days. Check the checkbox to acknowledge the change and then select Update Settings.

7. You will see a message showing that the update to Exchange Web Services (EWS) throttling policy has been successfully initiated. The update will complete within 15 minutes.

8. After 15 minutes run the test again to check if the changes are applied. This time you will see that Exchange Web Services (EWS) is currently not throttled.


  • Contact the Microsoft support team


Create a support request to ask Microsoft to disable the throttling.

The Office 365 support team can raise throttling limits on the following:


EwsMaxBurst : Unlimited
EwsRechargeRate : Unlimited
EwsCutoffBalance : Unlimited

(And highest limits available for EWSMaxConcurrency)

This is a standard procedure, and you can contact Microsoft support to get it changed. Typically for 90 days. These changes only affect Exchange, not SharePoint, OneDrive, or Groups.