Manage retention policies for Microsoft Teams

Note

If you are seeing a message in Teams that your chats or messages have been deleted by a retention policy, see Teams messages about retention policies.

The information on this page is for IT administrators who manage these retention policies.

Retention policies and retention labels from Microsoft 365 help you to more effectively manage the information in your organization. You can configure retention settings to keep data that's needed to comply with your organization's internal policies, industry regulations, or legal needs. You can also configure retention settings to delete data that's considered a liability, that you're no longer required to keep, or that has no legal or business value.

Teams supports retention policies for chat and channel messages so that as an admin, you can decide proactively whether to retain this data, delete it, or retain it for a specific period of time and then delete it. You can apply a Teams retention policy to your entire organization or to specific users and teams. Retention labels aren't supported for Teams.

To learn more about retention, and how you can apply retention settings by using retention policies or retention labels for other workloads in Microsoft 365, see Learn about retention policies and retention labels.

The minimum licensing requirement for retention policies for Teams is Microsoft 365 E3. To learn more about licensing, see Microsoft Teams service description.

How Teams retention/deletion policies work

Teams chat messages are stored in two locations. Primary copy is stored in Azure, a secondary copy, that is used for compilance policies, is stored in a hidden folder in the Exchange online mailbox of each user included in the chat, and Teams channel messages are stored in a similar hidden folder in the group mailbox for the team. When a chat message deletion policy is applied to a user or Team, secondary copy is deleted first, followed by primary copy. eDiscovery or Teams search is based off of messages stored in secondary copy and hence messages become non discoverable when secondary copy is deleted.

When a chat message retention poilcy is applied to a user or Team, and if the messages are deleted (either due to another deletion policy or by user themselves), the primary copy is deleted, hence Teams client will see the message disappear, but secondary copy is automatically moved to a hidden folder named SubstrateHolds , which is as a subfolder in the Exchange Recoverable Items folder. Until these messages are permanently deleted from the SubstrateHolds folder, they remain searchable by eDiscovery tools.

For detailed information about what's included and excluded for Teams retention policies, and how these policies work depending on your policy configuration, see Learn about retention for Microsoft Teams.

Note

That page explains why you might sometimes see delays when retention policies delete messages. For example, messages can be visible up to 7 days after the expiration period you've configured in the retention policy.

If you set up multiple Teams retention policies with different retention settings, the principles of retention resolve any conflicts. For example:

  • If there is a conflict between retaining or deleting the same content, the content is always retained.
  • If there is a conflict in how long to retain the same content, it is retained for the longest retention period.

These two principles of retention address most conflicts that might arise when you have multiple retention policies for Teams, but for more information, see The principles of retention, or what takes precedence?

When to use retention policies for Teams

In many cases, organizations consider private chat data as more of a liability than channel messages, which are typically more project-related conversations.

You can set up separate retention policies for private chats (1:1 or 1:many chats) and channel messages. You can also configure unique policies that apply to specific users or teams in your organization. For Teams chats, you can select which users the policy applies to. For Teams channel messages, you can select which teams the policy applies to.

For example, for channel messages, you can apply a one-year deletion policy to specific teams in your organization and apply a three-year deletion policy to all other teams.

Create and manage retention policies for Teams

To create a retention policy for Teams chats and channel messages, use the instructions from Retention policy for Teams locations.

That page has additional information about creating and managing retention policies for other workloads in Microsoft 365. For example, you might want to also create a retention policy for Microsoft 365 Groups to retain and delete files that are accessed in Teams and stored in OneDrive or SharePoint.

End user experience

For private chats (1:1 chats) or group chats, users will see that chats older than the retention policy configuration are deleted and an automatically generated message stating "We've deleted older messages due to your org's retention policy" is shown on top of yet undeleted messages. For example:

User informed in Teams that chat message are deleted because of a Teams retention policy

User in Teams explaining messages are deleted as a result of a Teams retention policy

For Channel messages, users (channel members) will see the deleted messages disappear from view after messages expire. If the deleted message was a parent message of a threaded conversation, then, in place of parent message, a message stating "This message has been deleted because of a Retention Policy" will be displayed. For example:

Screenshot of channel before retention

Screenshot of channel after retention

Note

The displayed messages that users see as a result of deleted messages are not configurable at this time.

The links in these displayed messages go to Teams messages about retention policies. This documentation for end users helps to answer basic questions about why their messages have been deleted. However, as part of your retention policy deployment, make sure that you communicate to users and your help desk the impact of your configured settings.