Microsoft 365 Groups

Manage Microsoft 365 Group mailboxes in Exchange Online. Microsoft 365 Groups provide a shared mailbox, calendar, document library, and other collaboration tools as a unified resource for teams.

Note: Microsoft 365 Groups are the recommended collaboration tool for teams. They integrate with Teams, SharePoint, Planner, and other Microsoft 365 services.

Group Mailbox List

Group Mailbox Features

Shared Inbox

Group mailbox provides a shared email inbox for the team:

• Members receive copies of messages sent to the group
• Conversations are threaded for easy reading
• Members can reply from the group address
• History is preserved for new members

Shared Calendar

Group calendar for team events and meetings:

• Schedule meetings visible to all members
• Book resources and rooms for the team
• Sync with personal Outlook calendars

Document Library

SharePoint document library connected to the group:

• Shared file storage for team documents
• Version history and co-authoring
• Accessible from Outlook, Teams, and SharePoint

Group Types

Public Groups

• Anyone in the organization can join
• Content visible to all organization members
• Appears in the global address list
• Discoverable in Outlook and Teams

Private Groups

• Membership controlled by owners
• Content visible only to members
• May be hidden from the global address list
• Join requests require owner approval

Managing Groups

Membership Management

• Add or remove members and owners
• Set up dynamic membership rules (Azure AD Premium)
• Configure self-service join options
• Manage guest (external) members

Email Settings

• Configure who can send to the group
• Set up moderation for incoming messages
• Manage email aliases and reply-to address
• Configure delivery options (inbox vs. group only)

Expiration Policy

Configure automatic group expiration:

• Set expiration period (e.g., 180 days)
• Owners notified before expiration
• Unused groups are automatically deleted
• Deleted groups can be recovered within 30 days

Best Practices

• Use M365 Groups for new teams — Preferred over distribution lists for collaboration.
• Assign multiple owners — Ensure at least two owners for each group.
• Configure expiration — Clean up unused groups automatically.
• Review guest access — Audit external member access regularly.

API Reference

GET /api/exchange/m365-groups List Microsoft 365 Groups

POST /api/exchange/m365-groups Create new group

GET /api/exchange/m365-groups/:id/members List group members

PUT /api/exchange/m365-groups/:id/settings Update group email settings

DELETE /api/exchange/m365-groups/:id Delete group