Shared Mailbox vs. Distribution List vs. Microsoft 365 Group

Shared Mailbox vs. Distribution List vs. Microsoft 365 Group

Microsoft 365 offers three ways to give a team one email address, and they behave very differently. Use a shared mailbox when a team needs one inbox and replies should come from the shared address, like info@ or billing@. Use a distribution list when a message should simply be copied to a set of people, like all-staff@. Use a Microsoft 365 group when a team needs a shared inbox plus a calendar, files, and usually a Team for working together. Picking the wrong one leads to missed messages, shared passwords, and licenses you did not need to buy.

Shared mailbox: one inbox for a team

A shared mailbox has its own address, inbox, and calendar. Members open it in Outlook next to their own mailbox, read and file messages, and reply as the shared address, so customers see “billing@” rather than an individual.

• Best for: info@, support@, billing@, orders@, a front desk, or any address customers write to where several people answer.
• Licensing: a shared mailbox does not need its own license up to 50 GB, as long as it does not need an archive or a hold that requires one.
• Security: people access it through their own accounts, so there is no shared password. Sign-in directly to the shared mailbox should be blocked.
• Watch out for: two people answering the same message. Agree on a simple rule, like moving handled messages to a folder or using categories.

Distribution list: copies to many inboxes

A distribution list is an address that forwards a copy of each message to every member’s own inbox. There is no shared inbox; each person sees the message in their own mailbox, and replies come from them personally.

• Best for: announcements and notifications, like all-staff@, managers@, or an alerts@ address that a few people need to see.
• Watch out for: lists that accept email from outside the company. An all-staff list that anyone on the internet can send to is an easy way to phish the whole company at once. Restrict large lists to internal senders.

Microsoft 365 group: email plus a workspace

A Microsoft 365 group comes with a shared inbox for conversations, a shared calendar, a SharePoint site for files, a Planner board, and it can be connected to Microsoft Teams. It is built for a team that works together, not just one that receives email together.

• Best for: project teams and departments that share files, meetings, and conversations.
• Watch out for: sprawl. When anyone can create groups and Teams, you end up with dozens of overlapping ones. Decide who can create them and how they are named.

Which one should you use?

• Customers or vendors write to the address and the team replies as that address: shared mailbox.
• A message should reach several people, who each handle it themselves: distribution list.
• A team shares files, a calendar, and chat, and sometimes email: Microsoft 365 group or Team.

Common mistakes

• A regular user mailbox used as a shared one, with a password passed around the office. It costs a license, defeats MFA, and nobody knows who sent what.
• A departed employee’s mailbox kept active with a license so others can check it. Convert it to a shared mailbox instead, which keeps the email, frees the license, and gives access to the right people. It is a standard step in our offboarding checklist.
• Forwarding rules instead of the right tool. A personal mailbox forwarding to five coworkers is a distribution list built badly.
• Nobody owns them. Every shared mailbox, list, and group should have an owner who reviews membership when people change roles.

Keeping access tidy

Membership in all three is controlled through Microsoft Entra ID and the Exchange admin center, which makes them easy to manage if they are assigned by role. Our explainer on Microsoft Entra ID covers how groups and access fit together, and a quick review of shared mailbox access each quarter catches people who no longer need it.

Microsoft 365, set up properly

Equal Tech Solutions’ Microsoft 365 services set up shared mailboxes, lists, and groups the right way, clean up the workarounds, and keep membership current for businesses across Cleveland, Chattanooga, and the Southeast. Contact us for help organizing your email.