Conducting Digital Investigations with eDiscovery on Microsoft Purview in 2026

Conducting Digital Investigations with eDiscovery on Microsoft Purview in 2026

April 1, 2026

Introduction: The Crucial Role of eDiscovery in Digital Investigation

By 2026, organizations generate and store massive volumes of data across a variety of communication and collaboration platforms such as Microsoft Teams, Outlook, SharePoint and Viva Engage. When a legal, regulatory or internal investigation need arises – such as an allegation of misconduct, a data breach or litigation – the ability to quickly identify, collect and review relevant information is essential. This process is known as eDiscovery [1].

Microsoft Purview eDiscovery has become the definitive platform for digital investigations within the Microsoft 365 ecosystem in 2026. It provides a complete workflow from in-place data preservation to advanced evidence review and export. With the integration of AI capabilities in 2026, eDiscovery is now capable of analyzing not only the content of emails and documents, but also the complex interactions between users and AI agents, helping investigators find the “needle in the haystack” much faster and more accurately [2].

Using eDiscovery in Microsoft Purview allows organizations to conduct investigations securely and efficiently, ensuring that chain of custody is maintained and evidence is preserved immutably. This technical and educational article will guide compliance, legal, and security professionals in leveraging the advanced capabilities of eDiscovery to conduct robust digital investigations [3].

What is Microsoft Purview eDiscovery?

eDiscovery on Microsoft Purview is a case management solution designed to identify and collect electronic evidence. Its main features in 2026 include:

  • Case Management: Allows you to create specific cases for each investigation, organizing custodians, data sources and search results in a single location.

  • Data Preservation (Legal Hold): Places data sources (mailboxes, websites, chats) on legal hold, preventing content from being deleted or modified, even if the user tries to do so.

  • Search and Collection: Uses advanced queries to search across the entire Microsoft 365 environment, collecting only content relevant to the investigation.

  • Advanced Review with AI (Premium Review): Uses AI to group similar documents, identify topics, perform sentiment analysis, and detect codes or encoded terms that may indicate malicious activity.

  • Support for AI Interactions: You can now collect and review prompts and responses from AI agents (such as Microsoft Copilot), providing a complete view of user actions.

  • Evidence Export: Allows you to export collected data in industry standard formats (such as PST or raw files) for external review or use in court.

Benefits of eDiscovery on Microsoft Purview

Using eDiscovery offers strategic advantages for the organization:

  • Speed of Investigation: Dramatically reduces the time needed to find critical information through AI-based research and analysis tools.

  • Cost Reduction: Eliminates the need to export large volumes of data to third-party tools, carrying out most of the screening and review within the Microsoft environment itself.

  • Chain of Custody Preservation: Ensures that data is collected and managed securely, maintaining the integrity of evidence for legal purposes.

  • Risk Minimization: Helps quickly identify compliance violations or misconduct, allowing the organization to take corrective action quickly.

  • Regulatory Compliance: Meets legal requirements for preserving and producing electronic documents in response to discovery requests.

Step-by-Step Guide: Conducting an Investigation with eDiscovery (Premium)

Let's break down the steps to conduct a thorough investigation using eDiscovery (Premium) on Microsoft Purview.

Step 1: Creating a Case and Adding Custodians

  1. Access the Microsoft Purview compliance portal: Navigate to compliance.microsoft.com.

  2. Go to eDiscovery (Premium): From the navigation menu, select eDiscovery > Premium.

  3. Create a New Case: Click on "Cases" > "Create a case". Give a name and clear description for the investigation (e.g. "Internal Investigation - Data Leak March 2026").

  4. Add Custodians: Go to the "Data sources" tab > "Add data source" > "Add new custodians". Select users whose data needs to be investigated. Purview will automatically identify your mailboxes, OneDrive and SharePoint sites.

  5. Put on Hold: When adding custodians, select the option to put your data on "Hold". This will ensure that no information is lost during the investigation.

Step 2: Conducting Research and Collections

  1. Create a New Collection: Go to the "Collections" > "New collection" tab.

  2. Define Search Criteria: Use the query builder to define specific keywords, date ranges, and senders/recipients.

  3. Include AI Interactions: Be sure to include the option to search AI chat logs and Copilot interactions if relevant.

  4. Run the Search: Purview will provide an estimate of the volume of data found. If the volume is too large, refine your query to reduce noise.

  5. Add to Review Set: Once satisfied with the search, select "Add to review set". This will process the data for advanced analytics, including extracting attachments and analyzing Teams conversations.

Step 3: Review and Analysis with AI

  1. Access the Review Set: Go to the "Review sets" tab and open the set you just created.

  2. Use AI Tools for Screening:

  3. "Conversation threading": Groups chat and email messages into logical conversations, making it easier to understand the context.

  4. "Near-duplicate detection": Identifies documents that are almost identical, allowing you to review just one of them.

  5. "Themes and predictive coding": The system identifies the main themes in the collected data. You can "train" the AI ​​by marking some documents as relevant or irrelevant, and it will suggest others based on your pattern.

  6. Tag the Evidence: Use tags to organize documents (e.g. "Confidential", "Relevant to the Case", "Attorney-Client Privilege").

Step 4: Exporting the Results

  1. Select Documents for Export: After review, select documents marked as relevant.

  2. Configure Export: Go to "Action" > "Export". Choose the output format (e.g. original files, PDF, payload files for other review tools).

  3. Download Export Package: The system will generate a secure link to download the evidence package along with a detailed export report for audit purposes.

Conclusion

eDiscovery on Microsoft Purview in 2026 is an indispensable tool for navigating the complexity of modern digital investigations. By providing an integrated, intelligent platform for data preservation, search, and review, Microsoft empowers organizations to respond to legal and compliance challenges with agility and accuracy. In the age of AI, where data is generated at unprecedented speeds and volumes, having a robust and native eDiscovery solution is essential to protect the integrity of the organization and ensure fairness and transparency in all investigative processes.

References

[1] Microsoft Purview eDiscovery. "Identify, review, and manage content in Microsoft 365 services." Available at: https://www.microsoft.com/en-us/security/business/risk-management/microsoft-purview-ediscovery [2] Microsoft Tech Community. "Microsoft Purview innovations announced at RSAC 2026." Available at: [https://techcommunity.microsoft.com/blog/microsoft-security-blog/secure-data-as-ai-scales-new-microsoft-purview-innovations-at-rsa-2026/4503665] (https://techcommunity.microsoft.com/blog/microsoft-security-blog/secure-data-as-ai-scales-new-microsoft-purview-innovations-at-rsa-2026/4503665) [3] Microsoft Learn. "Learn about eDiscovery in Microsoft Purview." Available at: https://learn.microsoft.com/en-us/purview/edisc