Granting access to an Online Archive (In-Place Archive) in Outlook 365 can be confusing for administrators and end users. Many expect that giving folder-level permissions (like Author or Reviewer) will work, but this isn’t the case. In this article, we’ll explain how Online Archive delegation works, what the limitations are, and the correct way to set it up.
What Is the Outlook Online Archive?
The Online Archive (also called In-Place Archive) is an additional mailbox attached to a user’s primary mailbox in Microsoft 365. It’s designed for long-term email storage and helps keep the primary mailbox within size limits.
Key points:
- It is separate from the main mailbox.
- It is only accessible online.
- It’s tied to the user’s Exchange Online license.
Can You Delegate Archive Access with Folder Permissions?
The short answer: No.
Folder-level permissions (such as Publishing Author, Editor, or Reviewer) do not extend to the Online Archive. If you want another user to see the archive, you must give them Full Access to the primary mailbox.
Full Access Is Required
With Full Access permissions, a delegate can open both the primary mailbox and its Online Archive. This is the only supported way to provide archive access.
Outlook Desktop
- If permissions are granted directly (not via a security group), Outlook automatically maps both the mailbox and the archive for the delegate.
Outlook on the Web (OWA)
- Delegates must use “Open another mailbox” to view the archive.
- The archive will not auto-map in OWA.
How to Grant Full Access
Via Microsoft 365 Admin Center
- Go to Exchange admin center.
- Select the mailbox.
- Under Mailbox delegation, add the delegate under Full Access.
Via PowerShell
Add-MailboxPermission -Identity "user@domain.com" -User "delegate@domain.com" -AccessRights FullAccess
⚠️ Important: Assign the permission directly to the user, not through a group, to ensure auto-mapping works in Outlook Desktop.
Troubleshooting Tips
| Problem | Fix |
|---|---|
| Archive not showing in Outlook | Verify Full Access is direct, not group-based. |
| Archive missing in OWA | Use “Open another mailbox” to manually load it. |
| Still not visible | Check licensing, update Outlook, or run Microsoft’s diagnostic tools. |
FAQ
Can I just grant folder-level permissions to the archive?
No, only Full Access permissions apply.
Does the archive auto-map everywhere?
- In Outlook Desktop: Yes, if permission is direct.
- In OWA: No, you must manually open the mailbox.
Conclusion
If you need to delegate access to an Outlook 365 Online Archive, remember: Full Access permissions are required. Folder-level delegation does not extend to archives. By assigning Full Access directly, you ensure the delegate can open both the mailbox and its archive, whether in Outlook Desktop or via OWA.
This approach provides the most reliable way to share archived mail in Microsoft 365.
