MC1472592 - Microsoft Purview: Auto-expanding archive capacity increases to 3 TB for eligible mailboxes
Microsoft 365 Message Center announcement MC1472592.
MS Message Center's Summary
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.
- Importance
- 4/10: This is a positive feature enhancement increasing storage limits with no mandatory administrator action required.
Microsoft Summary
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 Center ID
- MC1472592
- Category
- stay Informed
- Severity
- normal
- Services
- Microsoft Purview
- Tags
- Feature update, User impact, Admin impact
- Roadmap ID
- 560820
- Platforms
- Web
- Published
- 2026-09-15
- Last updated
- 2026-09-15
- Expires
- 2026-11-22
[What and why] 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. [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.