Teams Private Channels Reengineered: Compliance & Data Security Actions Needed by Sept 20, 2025
You may have missed this critical update, as it was published only on the Microsoft Teams blog and flagged as a Teams change in the Message Center under MC1134737. However, it represents a complete reengineering of how private channel data is stored and managed, with direct implications for Microsoft Purview compliance policies, including eDiscovery, Legal Hold, Data Loss Prevention (DLP), and Retention. 🔗 Read the official blog post here New enhancements in Private Channels in Microsoft Teams unlock their full potential | Microsoft Community Hub What’s Changing? A Shift from User to Group Mailboxes Historically, private channel data was stored in individual user mailboxes, requiring compliance and security policies to be scoped at the user level. Starting September 20, 2025, Microsoft is reengineering this model: Private channels will now use dedicated group mailboxes tied to the team’s Microsoft 365 group. Compliance and security policies must be applied to the team’s Microsoft 365 group, not just individual users. Existing user-level policies will not govern new private channel data post-migration. This change aligns private channels with how shared channels are managed, streamlining policy enforcement but requiring manual updates to ensure coverage. Why This Matters for Data Security and Compliance Admins If your organization uses Microsoft Purview for: eDiscovery Legal Hold Data Loss Prevention (DLP) Retention Policies You must review and update your Purview eDiscovery and legal holds, DLP, and retention policies. Without action, new private channel data may fall outside existing policy coverage, especially if your current policies are not already scoped to the team’s group. This could lead to significant data security, governance and legal risks. Action Required by September 20, 2025 Before migration begins: Review all Purview policies related to private channels. Apply policies to the team’s Microsoft 365 group to ensure continuity. Update eDiscovery searches to include both user and group mailboxes. Modify DLP scopes to include the team’s group. Align retention policies with the team’s group settings. Migration will begin in late September and continue through December 2025. A PowerShell command will be released to help track migration progress per tenant. Migration Timeline Migration begins September 20, 2025, and continues through December 2025. Migration timing may vary by tenant. A PowerShell command will be released to help track migration status. I recommend keeping track of any additional announcements in the message center.Microsoft Purview Best Practices
Microsoft Purview is a solution that helps organizations manage data and compliance. It also uses AI to classify data, monitor compliance, and identify risks. Key features include data discovery, classification, governence, retention, compliance management, encryption, and access controls. Purview ensures data security, prevents insider threats, and helps implement data loss prevention policies to meet compliance requirements. Hello everyone - This is just a short introduction, I am Dogan Colak. I have been working as an M365 Consultant for about 5 years, holding certifications such as MCT, SC-100, SC-200, SC-300, and MS-102, with a focus on Security & Compliance. This year, I am excited to share what I have learned with the Microsoft Technology Community. In the coming days, I will be publishing videos and articles based on the training agenda I have created. I will also share these articles on LinkedIn, so feel free to follow me there. I am always open to feedback and suggestions. See you soon!
Test DLP Policy: On-Prem
We have DLP policies based on SIT and it is working well for various locations such as Sharepoint, Exchange and Endpoint devices. But the DLP policy for On-Prem Nas shares is not matching when used with Microsoft Information Protection Scanner. DLP Rule: Conditions Content contains any of these sensitive info types: Credit Card Number U.S. Bank Account Number U.S. Driver's License Number U.S. Individual Taxpayer Identification Number (ITIN) U.S. Social Security Number (SSN) The policy is visible to the Scanner and it is being logged as being executed MSIP.Lib MSIP.Scanner (30548) Executing policy: Data Discovery On-Prem, policyId: 85........................ and the MIP reports are listing files with these SITs The results Information Type Name - Credit Card Number U.S. Social Security Number (SSN) U.S. Bank Account Number Action - Classified Dlp Mode -- Test Dlp Status -- Skipped Dlp Comment -- No match There is no other information in logs. Why is the DLP policy not matching and how can I test the policy ? thanks
Configuring Purview policy to email user's Leader for approval, using external HR Database
Hello, Wondering if anybody could confirm within Microsoft Purview if it is possible to: Have a DLP Policy configured with a Policy Tip Override and have it configured so if the email for example is blocked it sends a Notification to the users 'Leader' to either Accept or Deny it. If Accepted by the user's Leader, the content is released. In the same configuration have Purview user a Data Connector to say a SAP database that the HR Department uses or any type of external database to automatically determine the users leader??? If so, any Microsoft articles and or videos???? Also want this compatibility to also be used for any type of Policy for say a SIT, Sensitivity Label, Trainable Classifier etc. etc. Thank you kindly, J
Microsoft DLP creditcard too many false positive
Hi all, I am new to the DLP world and performing some tests in my company. I wanted to discover if/who is sharing credit card numbers, cvv, data expiry, full name and address, because with all the information someone can harm the victim, right? The problem I am having is when people share bank statements containing just credit card numbers, it gets triggered, which is so annoying too many false positives. Is anyone there experiencing the same thing and can assist? I created two policies and enabled both at the same time. The first one is using just the SIT Credit Card Number The second one I am using SIT Credit Card Number, All Full Names, All Physical Addresses Please let me know if you need more information. Thanks in advance TZ
