MC1472592 - Microsoft Purview: Auto-expanding archive capacity increases to 3 TB for eligible mailboxes

Updated September 28, 2026: We have updated the content. Thank you for your patience. 

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.

**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.