Office 365, Unified Groups
The best part of Unified Groups is that they can function like a shared mailbox and calendar in Office 365 email and that any individual can create these Unified Groups as they need.
Unified Groups are groups based exclusively in Office 365. Anyone in Office365 can create these groups by creating a Microsoft Team, which creates a Unified Group or from the Outlook Client.
To learn more about how to create and use Unified Groups, please refer to the Microsoft Office 365 Groups document: