Email Distribution List vs Microsoft 365 Group vs Shared Mailbox — Which to Use When

“I want to email the whole team in one address.” Three tools do this in Microsoft 365 — and picking the wrong one causes headaches for years. Here’s how to choose, then how to set it up.

Prerequisites

• Microsoft 365 admin permission (for org-wide distribution lists, Groups & shared mailboxes)
• Outlook access (any user can create a personal Contact Group in their own Outlook)
• Ten minutes

The three tools — one-line comparison

• Distribution List (DL) — one email address that fans out to a list of recipients. No shared inbox, no history. Old-school and simple.
• Microsoft 365 Group — a distribution list PLUS a shared inbox, shared calendar, SharePoint site, Teams channel, and Planner. The modern choice for a proper team.
• Shared Mailbox — a mailbox that multiple people can read from and send from as (e.g. info@yourdomain.co.nz). No auto-fan-out; incoming email sits in one inbox for the team to work through.

Which one when

Use a Distribution List when:

• You want a one-off blast address like all-staff@yourdomain.co.nz that just delivers to everyone’s individual inbox
• Nobody needs to track “who replied” — replies go direct to the sender
• You don’t need a shared calendar or SharePoint alongside it

Use a Microsoft 365 Group when:

• The group is an ongoing team (Sales, Finance, Northland Office) with shared work
• You want a shared inbox AND SharePoint documents AND a Teams channel AND a calendar in one
• You want members’ Outlook to include a “Groups” folder they can drop into

Use a Shared Mailbox when:

• You want customer-facing addresses like info@, sales@, accounts@
• The team needs to see, respond to, and mark as done shared incoming email
• You want to send FROM that address (e.g. info@) as a shared identity

Rule of thumb: customer-facing address → Shared Mailbox. Team collaboration → Microsoft 365 Group. One-way blast list → Distribution List.

How to set up a personal Contact Group in Outlook (no admin needed)

Good for: emailing a specific set of contacts you use often (e.g. your board, your project team) — just for YOU.

1. Open Outlook → People (bottom-left icon)
2. Click New contact group (top ribbon)
3. Give it a name (e.g. “Board members”)
4. Click Add members → From Outlook Contacts / Address Book / New Email Contact
5. Pick the people
6. Click Save & Close

Now, in a new email, type the group name in the To: field and Outlook expands it into all the members. Only you see this group — it lives in your Contacts, not the organisation.

How to set up an org-wide Distribution List (admin required)

1. Sign in to admin.microsoft.com
2. Left menu → Teams & Groups → Active teams & groups
3. Click the Distribution list tab → + Add a distribution list
4. Fill in name, email address (e.g. all-staff@yourdomain.co.nz), description
5. Add members
6. Under settings, decide: allow external senders? (usually no for internal DLs)
7. Save

Test by sending yourself an email to the new address. Should arrive in every member’s inbox within seconds.

Common mistakes to avoid

• Using a Distribution List when you needed a Shared Mailbox. Customers email info@, it fans out to five inboxes, nobody knows who’s replying, three people reply the same thing.
• Using a Shared Mailbox when you needed a Microsoft 365 Group. No shared calendar, no SharePoint documents, no Teams — you’ll end up with all three eventually anyway.
• Not setting an owner. When the person who created the DL/Group leaves, nobody can edit membership. Always assign at least two owners.
• Forgetting to remove ex-staff. DL/Group/Shared Mailbox membership needs to update the day someone leaves — not months later.

Related quick wins

• Set up Microsoft Bookings
• Set office hours in Outlook

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Managed LiveSupport clients get DL/Group/Shared Mailbox management, ownership audits, and offboarding built in. Learn about LiveSupport.