As a best practice to deploy Teams, I recommend all my clients to configure an expiration policy for inactive Teams or Office 365 Groups. With the increase in usage of Office 365 Groups, we will need to find a way to clean up unused groups. Expiration policies can help us remove inactive groups from the system and make things cleaner.

We can specify an expiration period on any inactive group that reaches the end of that period, and if not renewed, it will be deleted. The expiration period begins when the group is created, or on the date it was last renewed. Group owners will automatically be sent an email before the expiration that allows them to renew the group for another expiration interval. Groups that are actively in use are renewed automatically an no interaction from the owner is required. Any of the following actions will auto-renew a group:

• Using SharePoint – view, edit, download, move, share, or upload files.
• Using Outlook – join group, read or write group message from the group, and like a message (Outlook on the web).
• Using Teams – visiting a team’s channel.

I recommend starting with 6 months (180 days) policy and adapt based on end-user feedback. Keep in mind that activating the policy will trigger a renewal message to all owner of inactive group.

If you have setup retention policy in Security and Compliance center for groups, expiration policy works seamlessly with retention policy. When a group expires, the group’s conversations in mailbox and files in the group site are retained in the retention container for the specific number of days defined in the retention policy.

After activation of the policy, owners will receive the following message

To enable the policy

1. Open the Azure AD admin center with an account that is a global administrator in your Azure AD organization.
2. Select Groups, then select Expiration to open the expiration settings.
3. On the Expiration page, you can:
   1. Set the group lifetime in days. You could select one of the preset values, or a custom value (should be 31 days or more).
   2. Specify an email address where the renewal and expiration notifications should be sent when a group has no owner.
   3. Select which Office 365 groups expire. You can set expiration for:
      1. All Office 365 groups
      2. A list of Selected Office 365 groups
      3. None to restrict expiration for all groups
   4. Save your settings when you’re done by selecting Save