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Office 365 Groups

What Is an Office 365 Group?

Collaborating with colleagues can be challenging. When teams are working on a project together, there can be a lot to keep track of. Emails and meetings in Outlook, conversations and calls in Skype for Business, and documents to store and share in SharePoint Online and OneDrive for Business. Office 365 Groups enable teams to come together and get work done by establishing a single hub, with a single set of permissions across all these Office 365 apps, so teams can simplify collaboration and increase productivity. Office 365 Groups also allow collaboration in OneNote. When a user joins the group, they immediately gain access to all of the work of the team and project. Check out the video below to see how one team uses Office 365 groups and continue reading to learn more about Office 365 groups.

Platform Availability

Office 365 Groups are currently only available in Outlook Web App, Outlook 2016 for PC, and the Outlook Groups app for mobile devices. Outlook for Mac does not currently support this feature.

Public and Private Office 365 Groups

An Office 365 group can be public or private. A public group is open to everyone. If you just want to see what the group is doing, all the content and conversations are easy to view. But if the group interests you, you can join it and become a member. In most cases, a public group is your preferred alternative. On the other hand, a private group is exclusive and only open to its members. The content and conversations are secure and not viewable by everyone. Choose a private group when you are concerned about security and privacy, such as trade secrets or confidential information. Although anyone can see the name of the private group, information isn't accessible from search, links, or in other ways. Joining a private group requires approval from a group administrator. You can't change a public group into a private group, or a private group into a public group.

Although you can't participate in a private group that you aren't a member of, anyone can send email to a private group and even receive replies from that private group.

Group Owners and Group Members

There are a few things to call out about group members and owners.

When a group owner leaves your organization or team, all email, conversations, files, and calendar events are saved, so other group members can access the data. Please contact CDS Customer Care, in this case, to add a new group owner or promote another owner of the group. You should consider having multiple owners for a group in case there needs to be some management tasks and the group owner isn’t available.

  • A group can't have more than 10 owners.
  • A user can't create more than 250 groups.
  • Groups with more than a 1,000 members are supported, but group users may notice that accessing group conversations and the group calendar can take a long time.

Discovering and Joining Office 365 Groups

Before you can join an Office 365 group, you need to find it. Fortunately, groups are open and discoverable by default. To help you build a strong social network, take some time to discover existing groups and their members in your organization. If you know members of a group, their interests often coincide with yours. Finding groups first also avoids duplication of effort. Why create a group if one with the same purpose already exists? When you find a group that interests you, explore its membership, conversations, and files. Then decide whether to join the group and become an active participant.

Conversations and Email

To get things started and keep things going, an important part of any group is communication. A group has its own mailbox so all group emails are easy to locate and manage. In Outlook Web App, you can also have a conversation with group members by posting and replying to short messages. The entire history of conversations are preserved, helping new members get up to speed quickly.

Conversations are sorted by date from oldest to newest. You can quickly catch up with new conversation messages which are marked with a blue tab and even add attachments.

Occasionally, you might want to send an email message to the group, to ensure everyone gets the message right away. When you create the message, just type the group name on the To line.

Group Calendar

A dedicated group calendar helps all members coordinate their schedules. Everyone in the group automatically sees meeting invites and other events. If you belong to more than one group, it’s easy to view each group calendar side-by-side. Events that you create in the group calendar are automatically added and synchronized with your personal calendar. For events that other members create, you can add the event from the group calendar to your personal calendar, and the event automatically synchronizes with your personal calendar. Finally, you can overlay your personal calendar with a group calendar, to see how schedules align.

Files, Sharing, and OneDrive for Business

Sharing content, such as files and folders, is a hallmark of group collaboration. Shared content can live elsewhere in Office 365, but OneDrive for Business makes it convenient to view and edit files regardless of the actual location. Sharing content also helps unlock useful information hidden in mailboxes and personal folders. A group’s OneDrive for Business page is the primary place for group files, but you can access other shared and followed documents that you may need throughout the day to further collaborate with your group.

When you try to add a folder, if you get the error message, Operation is not valid due to the current state of the object, contact your agency administrator. Before you can add folders to your group files, your administrator must configure SharePoint to prevent users from running custom scripts on personal sites.


Whether you are tracking a Twitter feed, managing a project with Trello or watching the latest news headlines with Bing—Office 365 Connectors surfaces all the information you care about in the Office 365 Groups shared inbox, so you can easily collaborate with others and interact with the updates as they happen.

Each time a key activity takes place in the service you’re tracking—for example, when a new task is added to a Salesforce opportunity, an update is made to a Trello board or an incident is triggered in PagerDuty—a message is sent to the Groups shared inbox. You can then choose to share and discuss on the message with your team or take action with a few simple clicks.

Subscribing To a Group

When you subscribe to a group, you are requesting that conversations or events from the group be sent to your inbox. If you prefer to use Outlook instead of Outlook Web App, it’s a great idea to enable this feature, because it ensures that all members receive group email messages and calendar events in Outlook in a timely way so they can stay up-to-date on group activity. You can also reply to the conversations from Outlook, and the replies are immediately posted to the group conversation. Subscribing to a group is also helpful when you are actively working in different groups and related projects, and want to stay on the top of each conversation and calendar event from your inbox.

Subscribing is not enabled by default. You can enable subscribing for the group when you first create the group. After creating a group, you can also enable subscribing when adding a new member. Finally, each individual can enable or disable subscribing to suit their individual preferences.

If you think you are getting too much information from the group in your inbox, you can always unsubscribe from the group to reduce the information flow. The conversations are still available in the group, so you can revisit them from time-to-time to catch up on past conversations. There is a convenient unsubscribe link at the bottom of all group email messages.

Group naming policies

Group naming policies allows you to control how group names and email aliases appear in your organization's directory, and how they appear to users. You can require a specific prefix or suffix be added to the name for a distribution group when it's created. Group naming policies also lets you block specific words from being used in the group name. This helps you minimize the use of inappropriate words in group names.

For example, If you organization spans several different regions or countries, you can create a group naming policy that will add the region or country name to any group created. In this case, a group that gets created, called Example Agency Marketing, would look like this if your organization is in North America:

Name: (North America) Example Agency Marketing

Email alias:

If your company requires that group naming policies be turned on, contact CDS Customer Care for assistance.