(Updated) Microsoft Exchange Online: New limit for dynamic distribution groups (DDGs)

Message Center ID: MC1163757
Exchange Online
Plan for Change
Feature update User impact Admin impact
November 1, 2025
October 2025

Summary

Microsoft Exchange Online now limits each organization to a maximum of 3,000 dynamic distribution groups (DDGs). This change is active by default and cannot be disabled. Admins must remove existing DDGs before creating new ones once the limit is reached. No action is needed before rollout.

Details

Updated October 2, 2025: This feature update has already rolled out to the Production environment — the original message was intended for a different audience. We apologize for any inconvenience.

[Introduction]

We will soon introduce a new limit on dynamic distribution groups (DDGs) in Microsoft Exchange Online. Each organization will be limited to a maximum of 3,000 DDGs. After this limit is reached, admins will need to remove existing DDGs before creating new ones. 

[When this will happen:]

 This feature update has already rolled out to the Production environment.

[How this will affect your organization:]

If your organization has fewer than 3,000 DDGs, this change will not impact you. However, after your organization reaches this limit, you will not be able to create new DDGs until some existing DDGs are removed.

This change will be on by default and cannot be turned off by admins.

[What you need to do to prepare:]

  • The enforcement of the DDG limit will happen automatically by the specified date with no admin action required before the rollout.
  • You may want to notify your admins about this change and update any relevant documentation.
  • We recommend reviewing the usage of Dynamic Distribution Groups (DDGs) in your organization and removing any DDGs that are no longer needed.
  • You can use the Dynamic distribution groups report in the Exchange admin center (EAC) to see the number of DDGs in your organization and insights into their usage.
  • To access this report, go to the EAC > Reports > Mail flow > Dynamic distribution group report.

Learn more: 

[Compliance considerations:]

No compliance considerations identified, review as appropriate for your organization.

Change History

October 3, 2025 at 12:30 AM Updated
Summary
Previous
Microsoft Exchange Online will limit each organization to 3,000 dynamic distribution groups (DDGs) starting November 2025. Once the limit is reached, new DDGs cannot be created until existing ones are removed. The change is automatic and cannot be disabled. Admins should review and manage DDG usage accordingly.
New
Microsoft Exchange Online now limits each organization to a maximum of 3,000 dynamic distribution groups (DDGs). This change is active by default and cannot be disabled. Admins must remove existing DDGs before creating new ones once the limit is reached. No action is needed before rollout.
Last Updated Date
Previous
2025-10-02T16:45:19.393Z
New
2025-10-02T22:31:53.283Z
Body Content
Previous

Updated October 2, 2025: We have updated the title. Thank you for your patience.

[Introduction]

We will soon introduce a new limit on dynamic distribution groups (DDGs) in Microsoft Exchange Online. Each organization will be limited to a maximum of 3,000 DDGs. After this limit is reached, admins will need to remove existing DDGs before creating new ones. 

[When this will happen:]

General Availability: We will begin rolling out in early November 2025 and expect to complete by mid-November 2025.

[How this will affect your organization:]

If your organization has fewer than 3,000 DDGs, this change will not impact you. However, after your organization reaches this limit, you will not be able to create new DDGs until some existing DDGs are removed.

This change will be on by default and cannot be turned off by admins.

[What you need to do to prepare:]

  • The enforcement of the DDG limit will happen automatically by the specified date with no admin action required before the rollout.
  • You may want to notify your admins about this change and update any relevant documentation.
  • We recommend reviewing the usage of Dynamic Distribution Groups (DDGs) in your organization and removing any DDGs that are no longer needed.
  • You can use the Dynamic distribution groups report in the Exchange admin center (EAC) to see the number of DDGs in your organization and insights into their usage.
  • To access this report, go to the EAC > Reports > Mail flow > Dynamic distribution group report.

Learn more: 

[Compliance considerations:]

No compliance considerations identified, review as appropriate for your organization.

New

Updated October 2, 2025: This feature update has already rolled out to the Production environment — the original message was intended for a different audience. We apologize for any inconvenience.

[Introduction]

We will soon introduce a new limit on dynamic distribution groups (DDGs) in Microsoft Exchange Online. Each organization will be limited to a maximum of 3,000 DDGs. After this limit is reached, admins will need to remove existing DDGs before creating new ones. 

[When this will happen:]

 This feature update has already rolled out to the Production environment.

[How this will affect your organization:]

If your organization has fewer than 3,000 DDGs, this change will not impact you. However, after your organization reaches this limit, you will not be able to create new DDGs until some existing DDGs are removed.

This change will be on by default and cannot be turned off by admins.

[What you need to do to prepare:]

  • The enforcement of the DDG limit will happen automatically by the specified date with no admin action required before the rollout.
  • You may want to notify your admins about this change and update any relevant documentation.
  • We recommend reviewing the usage of Dynamic Distribution Groups (DDGs) in your organization and removing any DDGs that are no longer needed.
  • You can use the Dynamic distribution groups report in the Exchange admin center (EAC) to see the number of DDGs in your organization and insights into their usage.
  • To access this report, go to the EAC > Reports > Mail flow > Dynamic distribution group report.

Learn more: 

[Compliance considerations:]

No compliance considerations identified, review as appropriate for your organization.

October 2, 2025 at 6:30 PM Updated
Title
Previous
Microsoft Exchange Online: New limit for dynamic distribution groups (DDGs) for Microsoft 365 operated by 21Vianet
New
(Updated) Microsoft Exchange Online: New limit for dynamic distribution groups (DDGs)
Summary
Previous
Microsoft Exchange Online will limit each organization to 3,000 dynamic distribution groups (DDGs) starting November 2025. Once the limit is reached, new DDGs cannot be created until others are removed. This change is automatic, cannot be disabled, and admins should review and manage existing DDGs accordingly.
New
Microsoft Exchange Online will limit each organization to 3,000 dynamic distribution groups (DDGs) starting November 2025. Once the limit is reached, new DDGs cannot be created until existing ones are removed. The change is automatic and cannot be disabled. Admins should review and manage DDG usage accordingly.
Last Updated Date
Previous
2025-10-01T22:34:25.767Z
New
2025-10-02T16:45:19.393Z
Tags
Previous
Feature update,User impact,Admin impact
New
Updated message,Feature update,User impact,Admin impact
Body Content
Previous

[Introduction]

We will soon introduce a new limit on dynamic distribution groups (DDGs) in Microsoft Exchange Online. Each organization will be limited to a maximum of 3,000 DDGs. After this limit is reached, admins will need to remove existing DDGs before creating new ones. 

[When this will happen:]

General Availability: We will begin rolling out in early November 2025 and expect to complete by mid-November 2025.

[How this will affect your organization:]

If your organization has fewer than 3,000 DDGs, this change will not impact you. However, after your organization reaches this limit, you will not be able to create new DDGs until some existing DDGs are removed.

This change will be on by default and cannot be turned off by admins.

[What you need to do to prepare:]

  • The enforcement of the DDG limit will happen automatically by the specified date with no admin action required before the rollout.
  • You may want to notify your admins about this change and update any relevant documentation.
  • We recommend reviewing the usage of Dynamic Distribution Groups (DDGs) in your organization and removing any DDGs that are no longer needed.
  • You can use the Dynamic distribution groups report in the Exchange admin center (EAC) to see the number of DDGs in your organization and insights into their usage.
  • To access this report, go to the EAC > Reports > Mail flow > Dynamic distribution group report.

Learn more: 

[Compliance considerations:]

No compliance considerations identified, review as appropriate for your organization.

New

Updated October 2, 2025: We have updated the title. Thank you for your patience.

[Introduction]

We will soon introduce a new limit on dynamic distribution groups (DDGs) in Microsoft Exchange Online. Each organization will be limited to a maximum of 3,000 DDGs. After this limit is reached, admins will need to remove existing DDGs before creating new ones. 

[When this will happen:]

General Availability: We will begin rolling out in early November 2025 and expect to complete by mid-November 2025.

[How this will affect your organization:]

If your organization has fewer than 3,000 DDGs, this change will not impact you. However, after your organization reaches this limit, you will not be able to create new DDGs until some existing DDGs are removed.

This change will be on by default and cannot be turned off by admins.

[What you need to do to prepare:]

  • The enforcement of the DDG limit will happen automatically by the specified date with no admin action required before the rollout.
  • You may want to notify your admins about this change and update any relevant documentation.
  • We recommend reviewing the usage of Dynamic Distribution Groups (DDGs) in your organization and removing any DDGs that are no longer needed.
  • You can use the Dynamic distribution groups report in the Exchange admin center (EAC) to see the number of DDGs in your organization and insights into their usage.
  • To access this report, go to the EAC > Reports > Mail flow > Dynamic distribution group report.

Learn more: 

[Compliance considerations:]

No compliance considerations identified, review as appropriate for your organization.

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