1. In a web browser navigate to, sign in, and select Outlook.
  2. Under the Groups section, select the name of the group.
  3. In the top right corner of the window, click on the Members section.
  4. Select Add Members.
  5. Enter the names of the members to add
  6. Select Save in the top left corner of the pane.
Navigate to the group in and click the Members button and then Add members.