MC1281505 – M365 Change Digest

One-line summary

Azure PST Import enables admins to import PST files from Azure Blob Storage into Exchange Online mailboxes via PowerShell only, with rollout starting August 31, 2026.

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Details

RoadmapIds

557559

Summary

Azure PST Import enables Microsoft 365 admins to import PST files from Azure Blob Storage into Exchange Online mailboxes using PowerShell. The process includes readiness analysis, import execution, and cleanup, with no GUI available. It starts globally on August 31, 2026, requiring specific Azure permissions and mailbox prerequisites. Imported data follows existing retention and compliance policies.

Platforms

Web

Body (from Message Center)

Updated May 5, 2026: We have updated the timeline. Thank you for your patience.

[Introduction]

Azure PST Import provides a structured, PowerShell-based way for administrators to import PST files stored in Azure Blob Storage into Exchange Online mailboxes, which are commonly used to store archived Outlook mailbox content. This capability helps organizations migrate historical email data in a controlled and auditable way by validating readiness before importing and by providing reports throughout the process. The process starts by creating an Azure PST Import endpoint to establish the connection between Azure storage and Exchange Online. Administrators then run a migration batch in Analyze mode to review readiness and validate the input before proceeding. Once the analysis results are reviewed, they use those results to create and start the import batch, which begins importing the PST files into the specified mailboxes.

This message is associated with Microsoft 365 Roadmap ID 557559.

[When this will happen]

Global rollout

Start: August 31, 2026 (previously May 4)
Complete: September 1, 2026 (previously May 15)

[How this affects your organization]

Who is affected

Microsoft 365 administrators managing Exchange Online
Administrators using Microsoft Purview Data Lifecycle Management
Organizations that import PST files into user or archive mailboxes

What will happen

Administrators complete the Azure PST Import process using PowerShell cmdlets only.
The workflow includes:
- Creating an Azure PST Import migration endpoint
- Running a migration batch in Analyze mode to validate readiness
- Reviewing analysis results and reports
- Creating and starting the import batch
- Performing post-import cleanup
This experience is not available through a graphical user interface (GUI).
Existing mailbox prerequisites and quotas are validated before importing begins.
There is no direct user impact; the feature is admin-driven.

[What you can do to prepare]

Ensure your Azure storage account and container exist and are reachable; the endpoint creation cmdlet validates both during setup.
Grant the Storage Blob Data Reader role to the Office 365 Import Service app on the target storage account. Without this permission, creating the Azure PST Import endpoint will fail.
Prepare your batch input files (XML and/or CSV) and run the migration batch in Analyze mode first so the service can validate readiness before importing.
Confirm analysis prerequisites for target mailboxes:
- Appropriate license assigned
- Mailbox is not inactive or soft-deleted
- Recipient type is UserMailbox
- Archive is enabled if importing to archive
- Quota validations (ArchiveQuota / RecoverableItemsQuota) occur during analysis
Validate PST files ahead of time:
- Analysis verifies that all specified PST files exist
- PST file size is validated during analysis

For detailed cmdlet usage and guidance, review the Azure PST Import documentation on Microsoft Learn.

[Compliance considerations]

Question	Answer
Does the change alter how existing customer data is processed, stored, or accessed?	Yes. The feature enables administrators to import existing customer email data contained in PST files into Exchange Online mailboxes, where the data is then stored and processed according to existing Exchange Online behaviors.
Does the change store customer data, and if so, where is it stored?	Yes. PST file contents are imported into Exchange Online mailboxes within the customer’s Microsoft 365 tenant and are stored according to the tenant’s data residency and storage configuration.
Does the change modify retention policies, holds, or deletion workflows?	Yes. Once imported, mailbox data becomes subject to any existing Microsoft Purview retention policies, retention labels, holds, and deletion workflows already configured for the target mailboxes.
Does the change affect audit logging capabilities?	Yes. Administrative actions related to PST import and the resulting mailbox changes are logged using existing Exchange Online and Microsoft Purview audit logging mechanisms.
Does the change alter how admins can monitor or demonstrate compliance?	Yes. Administrators can use existing Exchange Online and Microsoft Purview reporting and audit tools to monitor PST import activity and demonstrate compliance after the data is imported.
Does the change include an admin control?	Yes. The feature is controlled through administrator access to PowerShell cmdlets and Azure role assignments, including permissions on the Azure storage account used for PST import.

Raw JSON (for debugging)

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