Disable EWS Throttling in Office 365

EWS throttling in Office 365 is one of the most common reasons for slow mailbox migrations, connection timeouts, and Exchange Online throttling errors. If your migration is taking longer than expected or frequently failing, throttling limits are likely affecting your performance.

Exchange Online uses throttling policies to control how applications access mailboxes through Exchange Web Services (EWS). While these limits are essential for maintaining system stability, they can significantly impact large-scale migrations. In this guide, you’ll learn how to reduce EWS throttling impact, request temporary limit increases, and improve overall migration speed in Exchange Online.

What is EWS Throttling in Exchange Online?

EWS throttling in Exchange Online is a control mechanism that limits how applications access mailboxes using Exchange Web Services (EWS).

Microsoft applies these throttling policies to prevent excessive usage and ensure stable performance across all users. Without these limits, heavy operations like large mailbox migrations or bulk data access could impact overall service availability.

EWS throttling typically controls:

• Number of concurrent connections.
• Frequency of API requests.
• Mailbox access operations.
• Data processing limits.

When these limits are exceeded, Exchange Online temporarily restricts further requests, which can slow down or interrupt migration processes.

How to prevent EWS throttling in Office 365

Completely preventing EWS throttling in Office 365 is not possible, as it is controlled by Microsoft to maintain service stability. However, you can significantly reduce EWS throttling impact in Exchange Online by following best practices.

• Maintain sufficient intervals between multiple migration batches.
• Avoid running heavy concurrent tasks during the migration process.
• Limit the frequency of requests to the same mailbox during Office 365 operations.
• Minimize unnecessary activities within the mailbox during migration.

Steps to increase EWS throttling policy limits in Microsoft 365

Modifying throttling policies in Exchange Online manually is no longer possible. Earlier, administrators could adjust these settings using remote PowerShell, but Microsoft has now restricted that capability. However, you can temporarily request an increase in EWS throttling limits through the Microsoft 365 Admin Center or by contacting Microsoft Support for assistance.

1. Sign in to your Microsoft 365 Admin Center account
2. Click ‘…Show all’ on the left side menu.

   

3. Navigate to ‘Support’ > ‘Help & support’

   

4. Type ‘Increase EWS Throttling Policy’ in the search bar, press the Enter key, then click the ‘Run Tests’ button

   

5. Wait till the diagnostic test completes. Next, choose either 30, 60, or 90 days to disable the EWS Throttling Policy. Ensure to check the acknowledgement checkbox and then click the ‘Update’ button

   

6. Exchange Web Services (EWS) throttling policy updates have been started. It will be completed within 15 minutes.
7. After 15 minutes, perform the test (Step 4) to confirm that the throttling has been disabled.

How EdbMails Helps Handle EWS Throttling in Office 365

Managing EWS throttling in Office 365 can be challenging, especially during large-scale migrations. Using the right tool can make a significant difference in reducing throttling issues and improving overall performance.EdbMails is designed to efficiently handle EWS throttling in Exchange Online, ensuring smooth and reliable mailbox migrations.

Key Advantages of Using EdbMails

• Controls the number of concurrent mailbox connections to avoid throttling.
• Manages request frequency to stay within EWS limits.
• Automatically handles throttling responses during migration.
• Ensures stable mailbox processing under Exchange Online throttling conditions.

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Additional Resources:

• Enable MFA in Office 365
• Create App password for MFA
• Disable Security Defaults