Summary
- Microsoft Purview Data Lifecycle Management is increasing the maximum auto-expanding archive capacity for eligible Exchange Online archive mailboxes from 1.5 TB to 3 TB.
- The change applies only to mailboxes with auto-expanding archiving enabled and supported licenses; non-eligible mailboxes remain capped at 1.5 TB.
- No new configuration, user interface, retention, or hold changes are introduced, and there is no per-GB consumption charge for this update.
- Administrators should verify license eligibility, monitor archive growth, and update internal guidance for teams managing large archives.
Microsoft is increasing the auto expanding archive capacity for eligible Exchange Online mailboxes from 1.5 terabytes to 3 terabytes between mid October and late October 2026. This change occurs automatically with no additional costs or configuration required for mailboxes that already have the feature enabled. Administrators should verify licence eligibility and update internal documentation to reflect the new capacity limits.
Administrator impact: Verify license eligibility and update internal documentation to reflect the new capacity limits.
End user impact: Eligible archive mailboxes can now grow automatically up to 3 terabytes without manual intervention.
Score rationale: This is a positive feature enhancement increasing storage limits with no mandatory administrator action required.
Enable auto expanding archiving | Learn about auto expanding archiving
Microsoft Purview increases auto-expanding archive capacity for eligible Exchange Online mailboxes from 1.5 TB to 3 TB starting mid-October 2026. No extra configuration or charges apply. Administrators should verify license eligibility, monitor growth, and update documentation accordingly. Compliance impact is minimal.
Message ID: MC1472592
Primary Service: Purview
Admin Impact: Medium
User Impact: Low
Release Start: 15 Oct 2026
Release End: 31 Oct 2026
Published: 16 Sept 2026
Expires: 22 Nov 2026
Last updated: 29 Sept 2026
Service: Exchange, Outlook, Purview
Category: Stay informed
Tags: Feature update, User impact, Admin impact
Rollout: October 2026
Platforms: Web
Related Roadmap: 560820
History
Updated September 28, 2026: We have updated the content. Thank you for your patience.
9/15/2026 Item Added to Message Center
Microsoft Message
Microsoft Purview Data Lifecycle Management is increasing the maximum auto-expanding archive capacity for eligible Exchange Online archive mailboxes from 1.5 TB to 3 TB. This enhancement helps organizations retain and manage larger volumes of archived email content without requiring manual archive expansion processes or support requests. Eligible mailboxes with auto-expanding archiving enabled will continue to grow automatically as needed.
Rollout schedule
General Availability (Worldwide): Beginning in mid-October 2026 and expected to complete by late October 2026
Impact on your organization
Who is affected
- Organizations using Exchange Online archive mailboxes with auto-expanding archiving enabled
- Administrators responsible for Microsoft Purview Data Lifecycle Management and Exchange Online archiving
- Users assigned eligible licenses that support the increased archive capacity
Platforms and services
- Microsoft Purview Data Lifecycle Management
- Exchange Online
- Exchange Online Archiving
What will happen
- Eligible archive mailboxes with auto-expanding archiving enabled can automatically expand beyond the current 1.5 TB limit up to a maximum of 3 TB per mailbox.
- No additional configuration is required for eligible mailboxes that already have auto-expanding archiving enabled.
- No per-GB consumption charge is introduced as part of this change.
- Existing archive content, retention configurations, policies, and holds are unchanged.
- No new administrator workflow, user experience, or user interface is introduced.
- Mailboxes that do not have an eligible license will continue to be limited to 1.5 TB.
Eligible licensing includes:
- Office 365 E5, A5, and G5
- Microsoft 365 E5, A5, and G5
- Microsoft 365 Purview Suite
- Microsoft 365 Purview Suite FLW, EDU, and GOV
- Microsoft Defender + Purview Suite FLW
- Microsoft 365 F5 Compliance
- Microsoft 365 F5 Security + Compliance
- Combination of the eDiscovery & Audit and Insider Risk Management mini suites together with the Information Protection & Governance mini suite
Note: *The maximum auto-expanding archive capacity supported through this feature is 3 TB per mailbox for eligible licenses.
**This feature is available to customers licensed with Microsoft Purview E5 or higher qualifying offerings that include Purview E5 capabilities ex E7.
Action required and recommendations
No action is required if eligible mailboxes already have auto-expanding archiving enabled.
We recommend that administrators:
- Review license assignments for users with large archive mailboxes to confirm eligibility.
- Monitor archive mailbox growth using Exchange Online PowerShell.
- Identify mailboxes approaching their applicable archive capacity limits.
- Update internal documentation, retention guidance, and help desk materials to reflect the new 3 TB limit.
- Review licensing and retention strategies for users whose archive mailboxes are not eligible for the expanded capacity.
Learn more
- Enable auto-expanding archiving | Microsoft Learn
- Learn about auto-expanding archiving | Microsoft Learn
Compliance considerations
No compliance considerations identified. Review as appropriate for your organization.