Posted in Electronic records, Governance, Information Management, Microsoft 365, Microsoft Teams, Records management, Retention and disposal, SharePoint Online

A basic retention model for Microsoft Teams

In my previous post about managing inactive Teams, the third option listed was to apply retention policies to those Teams. It included the graphic below.

This post provides more details of a basic retention model that can be applied to both active and inactive Teams.

Key takeaways

Key takeaways from this post for records and information managers:

  • Every Team has a ‘Posts’ (group chat messages) and ‘Files’ (documents etc) tab, and usually also starts with a Wiki tab (which can be removed). Other tabs may be added via the + option.
  • A Team in Microsoft Teams is not a single container or aggregation for the capture and storage of records. Almost all the records in a Team are stored in a hidden folder in Exchange Online (EXO) mailboxes (posts) or SharePoint Online (SPO) (files). Some records (conversations) may also be created and captured in the EXO mailbox of the associated Microsoft 365 (M365) Group.
  • It is not possible to apply a single retention policy to a Team; at least two separate policies will be required – one policy for the Team channel posts of EVERY team, and one or more policies for the content captured in SPO sites (files) or groups of sites.
  • Some records, created in and accessible from Teams, may be stored in other M365 applications (e.g., Tasks, Forms, WhiteBoard, etc) or third-party applications. It is not possible to apply any Microsoft 365 retention policy to records created by or captured in these applications.
  • Records and information managers should have access to the details (not necessarily the content) of every M365 Group, Team, and SPO site in order to establish a plan for the creation and application of retention policies to Teams. At a minimum, they should be assigned the Global Reader role (for details of M365 Groups and SPO sites) and the Compliance admin role (for retention policies).
  • It is relatively easy to overcomplicate the retention model for Teams, for example by applying separate retention labels to different folders and sub-folders in each channel ‘files’ tab.
  • Try to keep the model simple for as long as possible.

Core components of a Team

The main components of every Team are shown in the diagram below. If private channels are not allowed in the organisation, ignore the top two left and right elements.

The relationship of a Team to its M365 Group, Exchange mailbox and SharePoint site, showing where the content is stored (dotted lines).

As shown in the diagram above:

  • Every Team is directly linked with an M365 Group. Every M365 Group has an Exchange Online (EXO) mailbox and a SharePoint Online (SPO) site.
    • The Team, M365 Group, SPO site, and mailbox address (teamname@) all share the same name. The original name (which should be brief, <20 characters if possible) and the display name may be different.
    • The Owners and Members of the Team are the Owners and Members of the M365 Group and those Groups are added to the SPO site Owners and Members permission groups respectively.
  • A ‘compliance copy’ of every post in a normal channel is copied from the Azure-based Teams chat service (which is always inaccessible) to a hidden folder of the EXO mailbox of the M365 Group linked with the Team.
    • Where private channels are allowed, a ‘compliance copy’ of every post in a private channel is copied to a hidden folder of the ‘personal’ EXO mailboxes of all participants in the private channel.
  • Any content created or captured in the ‘Files’ tab of the Team channels is stored in the SPO site of the M365 Group linked with the Team. If any lists are created, they are either stored on the same SPO site or are linked from another site.
    • Where private channels are allowed, a separate SPO site is created (using the name of the ‘parent’ site followed by a hyphen then the private channel name, e.g., parentsitename-privatechannelnamesite). Any content created or captured in the ‘Files’ tab is stored in that SPO site.

So, a Team is a combination of at least four elements: the Teams user-interface (and back-end database), an M365 Group, a SPO site, and an EXO mailbox. The mailbox is used for three main purposes:

  • Email-based ‘conversations’ (when used).
  • Calendaring.
  • Storage of Teams posts.

This is why it is not possible to apply a single retention policy to a Team.

The basic retention model

The basic retention model for Teams assumes the following:

  • If the organisation’s retention schedule/disposal authority does not include coverage for Team posts (chat messages) and also general Team chats, there is a legally defensible policy that defines how long Team channel (including private channel) posts (and chats) will be retained. Note: This policy will define a single retention period for ALL posts and and a separate policy for ALL chats.
  • Records and information managers know the details of every M365 Group, Team (including number of private channels) and SPO site (including last activity and number of files).
  • One or more retention policies will be created for SPO sites.
  • One or more retention policies may be created for M365 Groups.
  • Unless it is done ‘manually’, there will be no review process before the content is destroyed at the end of the retention period.
  • No label-based retention policies will be applied (at this point). They may be added later as required (see below).
  • Unless the option to auto-expiry M365 Groups is used, there will be a manual process to delete inactive and empty M365 Groups or Teams; deleting either will also delete the linked SPO site.

Creating retention policies

Retention policies are created in the Information Governance section of the M365 Compliance admin portal under ‘Retention policies’.

Generally speaking, organisations should not create many of these policies as they should ideally target entire workloads (all SPO sites, all EXO mailboxes, etc) or in some cases major groupings (e.g., EXO mailboxes of senior executives, all other mailboxes).

And remember, these policies do NOT destroy the container (Team, SPO site, EXO mailbox), only the content in those containers.

Every new retention policy has three parts.

Name

The name of the retention policy should be easily recognisable, for example ‘Teams channel posts 7 years’ (all encompassing, for all channel posts, see next dot point), or ‘General SPO site retention 7 years’. The name section also includes a description that should always be used to link the policy to details in a retention schedule/disposal authority or corporate policy.

Location

The ‘location’ element is where the complexity arises as it is not possible to create a single retention policy for all the elements in a Team. Selecting either ‘Teams channel messages’ or ‘Teams private channel messages’ will disable all other options. It is not possible to select ‘SharePoint sites’ or ‘Microsoft 365 Groups’ AND any of the Teams options in the same policy.

Because of this limitation, at least two separate retention policies will be required for a basic retention model, with an additional one for private channels (if required):

  • A retention policy for either all or selected SharePoint sites, including private channel sites. The simplest model is to create a single retention policy for all SharePoint sites. This creates a preservation hold library on every site, retaining all deleted content for the minimum period required. Alternatively, and especially if there is a way to ‘group’ SPO sites (e.g., all project team sites), create retention policies for those groups and add in the site names. Always keep in mind that a retention policy applied to the SPO site has no connection with or impact on the channel posts.
  • A retention policy for all Teams channel messages. Note that this cannot include or exclude any Teams – it’s all or none. Depending on the retention selected for channel posts (next point), this could mean that channel posts are destroyed before (or after) the Team’s SPO content.
  • A retention policy for all Teams private channel posts. Similar to the previous point, this is an ‘all or none’ policy.

If the Team is also making use of the M365 Group’s ‘conversations’ in Outlook, consideration may also be given to creating a retention policy for M365 Groups (or included/excluded Groups). This policy will cover (a) Group ‘conversations’ and (b) the SharePoint site linked with the Group/Team. It will NOT cover the Team channel posts that may be stored in the M365 Group EXO mailbox. Note: It is possible to select just the M365 Group mailbox OR the M365 Group’s SPO site in this policy via a PowerShell script.

Retention period

Retention options are shown in the screenshot below. These options are the same for every retention policy.

Retention policies either automatically delete content after a minimum period or do nothing (includes the ‘retain items forever’ option). There is no disposition review. This means that the content in the SPO site and Team channel (including any ‘deleted’ content, which is not actually deleted, just hidden) simply disappears when the retention period expires.

Retention variations

Organisations may of course have different requirements or decide to apply retention differently. Each of these will still be some variation on the above model.

In most cases, there should be at least one retention policy in place for each of the different elements that make up a Team – the M365 Group, the SPO site, the channel posts, the private channel posts. Whether those policies have the same retention period will be up the organisation to determine, but in all cases, the details should be documented somewhere as currently this information is not easily available.

Retention labels

It is not possible to apply retention labels to Teams channel or private channel posts (or chats). There is only one option, and that is a single retention policy for each of these.

Retention labels may be applied to the content stored in the Teams linked SPO site, and these may be applied instead of using retention policies. This may be an effective model when combined with auto-expiry of M365 Groups as this (auto-expiry) will not occur if the content is subject to an active retention policy or retention label.

However, applying labels to the content stored in each Team channel ‘files’ tab has the potential to be a very complicated model that will become almost impossible to monitor or manage in time.

Each channel ‘files’ tab maps to a folder with the same name in the Documents library of the linked SPO site. As each Team channel may have been created for the records of a different subject with a different retention requirement, this means that each folder (or potentially even sub-folders) in the library may have a different label.

As retention labels (and policies) apply to individual items in the library (but not the folder), this means that individual items, stored in folders, that are subject to disposition review will come up for review in the future.

The application of multiple retention labels to folders within the single Document library of the SPO site is already complicated; having to review some of the individual items as part of a disposition review in the future is just adding to the complexity.

My view is that Teams should, as far as possible, ‘contain’ records relating to the same subject with the same single retention period that can be applied to the entire SPO site. Applying individual labels to folders or sub-folders within a single document library is a complex model both to apply and manage into the future.

What do to with empty Teams?

As noted already, retention policies (and labels) do not delete the SPO site, Team or M365 Group, only the content stored in them. Each of these ‘containers’ remain after the content has been destroyed within them.

Accordingly, it is advisable for records and information managers to (a) have access to the details of every SPO site, Team and M365 Group and (b) work closely with IT to determine when these containers can be deleted (and document that activity). Otherwise, the M365 environment will be left with the hollow shells of sites, Teams and Groups.

Further reading

The following Microsoft links provide further details on this subject.

Learn about retention policies and retention labels

Learn about retention for Microsoft Teams

Learn about retention for SharePoint and OneDrive

Create and configure retention policies

Apply retention labels to files in SharePoint or OneDrive

Teams messages about retention policies

Featured image: http://www.pexels.com

Author:

I am an experienced information management professional based in Melbourne, Australia. I have had close to 40 years of practical working knowledge across the full spectrum of information, records and content management issues, and direct and practical experience with contemporary and emerging business and information and enterprise content management systems. My product knowledge includes SharePoint 2010/2013/Online and OneDrive (SharePoint Administrator), Office 365 (including as a Global Administrator), Yammer, Sway, TRIM Context (R6.2 & 7.1), ECM Documentum, Alfresco Share; and other online systems. www.andrewwarland.com.au

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