Distribution lists vs Microsoft 365 Groups
How DLs, mail-enabled security groups, and Microsoft 365 Groups differ — and when to use each.
There are at least four kinds of "group" in Microsoft 365 that can receive email, and they behave differently. Picking the right one prevents a lot of awkward conversations a year later.
1. Distribution lists (DLs)
The classic Exchange distribution list. Mail sent to it fans out to every member's personal inbox. There's no shared storage, no SharePoint site, no Teams. Two flavours:
- Mail-enabled security groups also work as permission groups, granting access to resources.
- Plain distribution lists are mail-only.
DLs are simple, fast, and the right tool for announcements and broadcasts to a static set of recipients.
2. Microsoft 365 Groups
A Microsoft 365 Group is much more than an address: each group has a shared mailbox, a SharePoint team site, a OneNote notebook, a Planner plan, and (optionally) a Microsoft Teams team. Members can choose whether mail to the group arrives in their personal inbox (subscribe), in the group's mailbox only, or both.
Microsoft 365 Groups are the right tool for teams that collaborate — they bring an entire workspace, not just a list.
3. Shared mailboxes
A shared mailbox is a single inbox that multiple people read and send from. Mail doesn't fan out — it lands in one place, and delegated users see it as a folder in Outlook. Use for support@, sales@, info@ — addresses where you want a queue, not personal copies.
4. Dynamic distribution groups
A dynamic distribution group is a DL whose membership is computed at send time from a query — "all users in the Sales department," "all employees in London." Use for very large groups where maintaining membership manually is impractical.
When to pick what
| Scenario | Tool |
| --- | --- |
| Announcement to all of HR | Mail-enabled security group or Microsoft 365 Group |
| Project team that needs Teams + files | Microsoft 365 Group |
| support@ queue handled by 3 agents | Shared mailbox |
| Department-wide newsletter | Dynamic distribution group |
| External contact list (vendors, customers) | Mail contacts inside a DL |
Modernisation
Microsoft's direction is Microsoft 365 Groups for new team-style work and distribution groups upgraded to Microsoft 365 Groups for legacy DLs where it makes sense. Mail-enabled security groups remain because they still serve as permission grants. Outright distribution lists are not deprecated, but they're rarely the best new choice.
When in doubt: if the group's members collaborate together, pick a Microsoft 365 Group; if they're just on the same broadcast list, pick a DL or dynamic DL.