Microsoft Purview eDiscovery Cannot Find Copilot Chat Content: Fix

When your organization runs an eDiscovery search in Microsoft Purview, you expect all relevant data to appear in the results. But many administrators find that Copilot chat content is completely missing from search results, even when the search parameters should include it. This happens because Copilot interactions are stored in a separate, hidden mailbox that Purview eDiscovery does not scan by default. This article explains the root cause of this issue and provides a step-by-step fix to ensure your eDiscovery searches include Copilot chat content.

Why Purview eDiscovery Misses Copilot Chat Content

Copilot chat interactions in Microsoft 365 are stored in a dedicated, system-managed mailbox per user. This mailbox is separate from the user’s primary Exchange Online mailbox. The mailbox is named in the pattern CopilotInteraction_<UserGUID>@<tenant>.onmicrosoft.com. Purview eDiscovery Standard searches only scan the primary mailbox and SharePoint sites by default. They do not automatically include the Copilot interaction mailbox. As a result, any search that targets a user’s mailbox will return zero Copilot chat results unless you explicitly add the Copilot mailbox as a data source.

The Copilot interaction mailbox is also not indexed for compliance search until mailbox auditing is enabled for it. Without auditing, Purview cannot discover or preview the content. This applies to both eDiscovery Standard and eDiscovery Premium workflows.

The Technical Root Cause

Each Copilot chat session is saved as a message in the user’s Copilot interaction mailbox. The message includes the user’s prompt, Copilot’s response, and metadata such as timestamp and conversation ID. Purview eDiscovery relies on the Exchange Online indexing service to crawl mailboxes. Because the Copilot interaction mailbox is a special system mailbox, the indexing service treats it as a hidden container. The eDiscovery search engine does not query it unless an administrator explicitly includes it via the data source configuration or PowerShell.

Steps to Include Copilot Chat Content in Purview eDiscovery

Follow these steps to configure Purview eDiscovery to find Copilot chat content. You need Exchange Online administrator permissions and Purview eDiscovery Manager role.

Step 1: Identify the Copilot Interaction Mailbox for Each User

1. Connect to Exchange Online PowerShell
   Open Exchange Online PowerShell as an administrator. Run Connect-ExchangeOnline and sign in with your admin credentials.
2. Retrieve the Copilot interaction mailbox
   Run the command Get-Mailbox -RecipientTypeDetails UserMailbox -Filter {DisplayName -like "CopilotInteraction"} | Format-List Name,PrimarySmtpAddress. This lists all Copilot interaction mailboxes in your tenant. Note the SMTP address for each user whose content you want to search.

Step 2: Enable Mailbox Auditing on the Copilot Interaction Mailbox

1. Run the auditing command
   For each Copilot interaction mailbox, run Set-Mailbox -Identity "CopilotInteraction_<UserGUID>@<tenant>.onmicrosoft.com" -AuditEnabled $true -AuditLogAgeLimit 365. This enables auditing for 365 days. Adjust the age limit as needed.
2. Verify auditing is active
   Run Get-Mailbox -Identity "CopilotInteraction_<UserGUID>@<tenant>.onmicrosoft.com" | Format-List AuditEnabled,AuditLogAgeLimit. Confirm the output shows AuditEnabled : True.

Step 3: Add the Copilot Interaction Mailbox to an eDiscovery Standard Search

1. Open Microsoft Purview compliance portal
   Go to https://compliance.microsoft.com and sign in with your admin account.
2. Navigate to eDiscovery Standard
   Select eDiscovery > Standard from the left navigation.
3. Create a new search or edit an existing one
   Click Create a search or open an existing search. Under the Locations tab, select Exchange mailboxes and then click Choose users, groups, or teams.
4. Add the Copilot interaction mailbox
   In the search box, paste the SMTP address of the Copilot interaction mailbox you retrieved in Step 1. Click Choose and then Done.
5. Run the search
   Click Submit to save and run the search. The results now include Copilot chat content from that mailbox.

Step 4: Add the Copilot Interaction Mailbox to an eDiscovery Premium Case

1. Open the Premium case
   In Purview, go to eDiscovery > Premium. Open the case you are working on.
2. Add a custodian
   Under the Sources tab, select Custodians > Add custodian. Search for the user whose Copilot content you need. Select the user and click Next.
3. Select the Copilot interaction mailbox as a data source
   On the Select data sources page, under Exchange, click Add. In the dialog, type the SMTP address of the Copilot interaction mailbox. Click Add and then Next.
4. Complete the custodian setup
   Review the settings and click Submit. The Copilot mailbox is now included in the case’s data sources.

If Copilot Chat Content Still Does Not Appear

Even after adding the Copilot interaction mailbox, you may encounter issues. Here are the most common problems and their fixes.

Copilot Interaction Mailbox Does Not Exist for a User

If the user never used Copilot, their interaction mailbox is not created. The mailbox is provisioned automatically after the first chat interaction. Ask the user to send at least one Copilot message and wait 15 minutes. Then re-run the PowerShell command from Step 1 to verify the mailbox appears.

Search Returns Zero Results Despite Correct Mailbox

This usually means auditing is still disabled on the mailbox. Re-run the auditing command from Step 2. After enabling auditing, allow up to 24 hours for the indexing service to crawl the mailbox. Run the eDiscovery search again after 24 hours.

eDiscovery Standard Does Not Support Multiple Mailbox Types in One Search

If you add both the user’s primary mailbox and the Copilot interaction mailbox to the same search, the search may fail due to a known limitation. Create two separate searches: one for the primary mailbox and one for the Copilot interaction mailbox. Then export and combine the results manually.

eDiscovery Premium Shows Copilot Content as Unindexed Items

If Copilot messages appear but are marked as unindexed, the mailbox auditing may have been enabled after the content was created. Only messages created after auditing was enabled are indexed. Enable auditing as soon as possible to capture future content. For historical content, you must use the Search-Mailbox cmdlet in PowerShell with the -SearchDumpster parameter to recover unindexed items.

eDiscovery Standard vs eDiscovery Premium for Copilot Content

Item	eDiscovery Standard	eDiscovery Premium
Mailbox type supported	Primary mailbox only by default	Primary mailbox, Copilot interaction mailbox, and other data sources
Adding Copilot mailbox	Must manually add mailbox SMTP in search locations	Must add as custodian data source in the case
Auditing requirement	Required for indexing and search results	Required for indexing and search results
Unindexed item handling	Shows as unindexed, cannot preview	Can review unindexed items in the case review set
Export options	Export results as PST or CSV	Export results with advanced processing, redactions, and tags

After completing the configuration, your Purview eDiscovery searches will include Copilot chat content. Start by enabling mailbox auditing on all existing Copilot interaction mailboxes in your tenant. Then add the appropriate mailboxes to your eDiscovery searches or cases. For ongoing compliance, create a PowerShell script that runs weekly to audit new Copilot interaction mailboxes automatically.