Microsoft 365 Groups is the membership service that sits behind collaboration in Microsoft 365: add someone to a group and they automatically get access to a shared Outlook inbox, a shared calendar, Planner, a SharePoint document library, a OneNote notebook and Clipchamp. If the group was created from Teams or Viva Engage, it brings a team or community with it too.
Here's the catch. A group isn't a mailing list. Creating one can spin up a SharePoint site, a shared inbox, a Planner and more, and if you lock down who can create groups, you also lock down who can create Teams and Planner. This is how it works as of October 2026.
What a single group gives your team
One membership list drives access to all of these at once:
- A shared Outlook inbox.
- A shared calendar.
- Planner.
- A SharePoint document library.
- A OneNote notebook.
- Clipchamp.
- A team in Teams or a Viva Engage community, if the group was created from there.
That's the point of groups. You add a new starter once and they get the inbox, the files and the plan, instead of you granting each one by hand. If you're setting up the Teams side, my guide on creating a team in Microsoft Teams walks through it.
Owners, members and guests
| Role | What they can do |
|---|---|
| Owner | Manage membership, settings and the shared inbox conversations |
| Member | Use every group resource; can't change settings; can invite guests by default |
| Guest | An external user who's been invited in |
Notice that last part of the member row. By default, members can invite guests. If your groups hold client files or pricing, decide on guest access before you add anyone.
The lock-down side effect
Any user can create a group unless you limit it. You might want to, to stop a sprawl of half-used groups. The trouble is what goes with it. If you restrict group creation, those users also can't create:
- SharePoint sites.
- Planner plans.
- Teams.
- Outlook group calendars.
- Clipchamp groups and Viva Engage groups.
- Shared OneDrive libraries.
- Power BI workspaces.
So if your team suddenly says they can't make a new team in Teams, a group creation limit is the first thing I'd check.
Who can manage groups, and from where
In the admin center, Teams & groups is where you create and manage Microsoft 365 groups, alongside Teams, distribution groups, security groups and shared mailboxes. User admins and group admins can create and manage groups there.
Delegated administrators, such as a consultant acting on your behalf, can't create or manage Microsoft 365 Groups. If you've handed your IT to an outside partner through delegated access, someone inside the business needs the right admin role for group work.
Admins can also set a naming policy, choose which domain groups use, control guest access, and scope some settings to a group. Loop's Cloud Policy settings, for example, can be assigned to a Microsoft 365 group.
Expiry and recovery
- With an expiration policy on, owners get renewal reminders 30 days, 15 days and 1 day before a group expires.
- Groups that aren't renewed are automatically deleted.
- A deleted group can be recovered within 30 days.
Expiry's useful for clearing out dead project groups, but make sure every group has an owner who reads their email. If nobody renews it, the group and its contents are deleted.
Group or shared mailbox?
Microsoft recommends a group over a shared mailbox when you have more than 25 users, need to stop people deleting messages, or need to give outsiders access. A shared mailbox can't do any of those. And you can't migrate a shared mailbox to a Microsoft 365 group later, so pick before the inbox fills up. If you only want one address that copies a few people in, an email distribution list is lighter still.
Want AI doing the heavy lifting in your marketing?
I build the systems that handle the boring 80 percent, so you get your week back. Done properly, with the human kept in.
Create your first group
- In the admin center, go to Teams & groups, then Active teams & groups.
- Add a Microsoft 365 group, name it, and add owners and members.
- Decide whether guests can be invited.
- If you'll end up with many groups, set an expiration policy and a naming policy.
My verdict on Microsoft 365 Groups
I'd use a group for any team or project that shares an inbox, files and a plan, especially once outsiders or more than 25 people are involved. Give every group two owners, decide on guests up front before client files go in, and switch on expiry if you'll make lots of them. Skip a group if all you need is a single address that forwards mail, and think twice before locking down creation, because it takes Teams and Planner with it.
If your team's collaboration set-up has grown messy, that's usually where I'd start before adding AI on top. I run AI training and workshops for teams, and help businesses with AI enablement, AI automation and GEO, which is about getting your business seen and cited in AI answers. Most of that work is with SaaS marketing teams, telecom companies and small businesses. Here's how we can work together.
Frequently asked questions
What does a Microsoft 365 group include?
A shared Outlook inbox, a shared calendar, Planner, a SharePoint document library, a OneNote notebook and Clipchamp, plus a team or Viva Engage community if created from there.
Can members invite guests to a Microsoft 365 group?
Yes, by default. Owners manage membership and settings, members use every resource, and guests are external users.
Can you recover a deleted Microsoft 365 group?
Yes. Admins can recover a deleted group within 30 days.
Can I convert a shared mailbox to a Microsoft 365 group?
No. A shared mailbox can't be migrated to a Microsoft 365 group, so decide which one you need early.
Who can create Microsoft 365 groups?
Any user, unless you limit creation. Limiting it also stops those users creating SharePoint sites, Planner plans, Teams, Outlook group calendars and Power BI workspaces.
What happens when a Microsoft 365 group expires?
Owners get renewal reminders 30 days, 15 days and 1 day before expiry. If nobody renews it, the group is automatically deleted, and it can be recovered within 30 days.
Can my IT consultant manage our Microsoft 365 groups?
Not through delegated admin access. Delegated administrators can't create or manage Microsoft 365 Groups; user admins and group admins in your organisation can.
