To set up groups in Office 365.
- Open Outlook on the web.
- In the navigation pane, next to Groups, select the + button. (If you don't see the + button, hover your mouse over the navigation pane.)
- In Choose a name, enter a group name that briefly captures the spirit of the group.
- A suggested group ID is provided. To assign a different name to your group which will be part of the group URL, click Edit next to the Group ID box.
- If you see "not available," the group ID is already in use. Try something different. Note that once you choose a group ID, it cannot be changed.
- In Add a description, enter a detailed description of the group to help others understand its purpose. This description will be included in the welcome email when others join the group.
- In Privacy, do one of the following:
- To create a group in which anyone can view its content and become a member, select Public.
- To create a group which requires approval by a group owner and only members can view group content, select Private.
- Optionally enable Subscribe members so they receive group conversations and calendar events in their inbox.
- This is recommended when members belong to multiple groups because it means they can see all group notifications in one place without having to visit each group mailbox in order to stay current with group activity.
- Select Create.
- If you're ready to add members to your newly created group (you aren't able to add external users at this time), continue with the create group wizard. Otherwise, select Not now. You can always come back and add group members later.
Now you and the members of your group can start collaborating!
For these same steps with images, and for the steps for creating groups in Outlook 2016 see Create a Group in Outlook
page on the Microsoft support site. (URL is included below as well.)