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.Disable-Mailbox -Archive in EXO with M365 Retention Policies assigned
Hello, working with a client that has 3 M365 retention policies assigned org-wide: 1. For All EXO mailboxes and all SPO/OneDrive's 2. For Teams Chats - all users/Teams 3. For Teams everything else - all users/Teams I'm unable to exclude a mailbox from #2 or #3 via Set-RetentionCompliancePolicy -AddExchangeLocationException, due to error TL;DR: this policy controls teams and Exchange settings are not allowed to be changed. I'm unable to do Disable-Mailbox -Archive, as the error tells me about the Teams policy #3 above being assigned (which indeed shows up in Get-OrganizationConfig). User's InPlaceHolds properly shows -mbx<guidOfPolicy#1Above>, and DelayHoldApplied/DelayReleaseHoldApplied both set to False. I'm unable to do Set-Mailbox -ExcludeFromAllOrgHolds, because that is only allowed on Inactive Mailboxes. Same goes for Set-Mailbox -ExcludeFromOrgHolds. My use case - UserMailbox which was enabled with an online Archive is now converted to a SharedMailbox, only requires <50GB, and no Archive. Archive is not even allowed per the EXO Service Descriptions for an un-licensed SharedMailbox. I find no way to drop the Archive mailbox successfully. This is fine, except the hypothetical scenario where the users of this SharedMailbox start to place items into the Archive, and then Microsoft invents something which takes away Archive mailboxes from un-licensed accounts. Not sure if that will ever happen, but I see no way to get this done and be on the right side of the license terms. Any ideas?
SharePoint Retention Labels / Policies
Morning. We are using SharePoint to create (and replace) are current Departmental Drives and we are going to move all the documents on the Drives to the relevant sites. We want to apply retention policies to all documents, but not sure how to make it work in this case. Retention counts from the date the file was created or modified in SharePoint - for the sake of this question, lets say that is Today. So if we are to keep document X for 5 years, that will be 5 years from today. Now, Document X was actually created 4 years ago, so technically it should be deleted in 1 year. But since i am moving it to SharePoint today, It will only be deleted in 5 years from today making the file 9 years old. Is there any way to apply policies that will work with files that are not newly created in SharePoint but moved from another location? thanks
SharePoint Retention - How have you applied it?
Hi all, I'm starting to look at retention in SharePoint. Currently using SharePoint as a document management system (replaced our drives) and one of the benefits was to utilise retention to avoid hoarding documents going back 20 years! So it would be great to hear how you have applied it and experiences with it: do your organisations staff have to manually tag the document or have you automated the retention label based on content type? do you have just the standard - after x years delete. Or do you have a review, i.e. untouched documents after 18 months will be pinged to the owner to confirm whether it should remain (and then stay for the remaining retention period) or whether it's no longer needed and can be deleted? Looking forward to hearing others experiences!Retention Policies set to delete files not working in SharePoint on new E3 trial tenant
I spun up an O365 E3 trial to do testing for a customer. I have created a few Retention policies (not labels) - the one that should be the most simple is not working at all: Delete after 2 days, based on last modified date Published to a single site I tried first to retain for 2 days and then delete, when that didn't work, I tried to just delete if it reaches 2 days, no retention at all. I've triple checked that the policy is applied to the site I'm working in. I created and uploaded files to the Libraries both before and after applying the policy the site, as well as 24 hours after publishing the policy. A week later, nothing has been deleted. Any ideas?
