Workplace
Shared mailbox or distribution list: what is the difference?
Short answer
A shared mailbox is one inbox that several people work in: everyone sees the same mail, and what one person answers, the others can see. A distribution list is only an address that forwards mail to each person's own inbox, with no shared overview. For info@ and invoices@ you almost always want a shared mailbox. A distribution list suits messages everyone must read and nobody has to handle.
What is a shared mailbox?
An inbox that belongs to nobody in person. It has its own address, such as info@ or invoices@, its own inbox and its own folder of sent messages. Colleagues with access see it appear in Outlook under their own mailbox.
The main point: there is one truth. A mail that has been read has been read for everyone. A reply that has been sent is there for everyone to see. When someone goes on holiday, nothing sits waiting in a personal inbox.
What is a distribution list?
An address without an inbox. Mail sent to that address is copied to everyone on the list and lands in each person’s own inbox. That is where it ends.
This works well for messages that only need to be read: an announcement to all staff, a newsletter from a supplier. It works badly for mail that someone has to act on. Five people get the same question from a customer. Two replies, or none from all five, because each assumes someone else is doing it.
How do the three compare?
| Shared mailbox | Distribution list | Microsoft 365 group | |
|---|---|---|---|
| Where the mail goes | Into one shared inbox | Into everyone’s own inbox | Into a group inbox, optionally to everyone as well |
| Replying from the shared address | Yes | Only with extra permissions | Yes |
| Seeing what a colleague replied | Yes | No | Yes |
| Files and Teams included | No | No | Yes |
| Licence | Not needed up to 50 GB | Not needed | Not needed, members do need one |
Which one do you choose for which address?
- info@, sales@, invoices@, applications@: a shared mailbox. Something has to happen with the mail, and you want to see that it happened.
- everyone@ or office@: a distribution list. It is a message, not a task.
- A project team or department that also shares documents: a Microsoft 365 group, usually through a team in Teams.
- The address of a colleague who has left: convert it to a shared mailbox, so the correspondence stays readable without paying for a licence. More on that in employee leaving.
What goes wrong in practice?
We keep running into three things.
Info@ is an ordinary account with a shared password. Everyone signs in with the same details. Two-step verification is off, because it does not work with five people. This is exactly the kind of account attackers look for. Converting it to a shared mailbox fixes that and saves a licence.
Info@ is a distribution list. Nobody knows whether a customer got a reply. It comes out when the customer writes for the third time.
The shared mailbox has no owner. Everyone can get in, so nobody feels responsible. That is not a technical problem. Agree who empties the inbox every day and who takes over when they are away.
Can you turn a distribution list into a shared mailbox?
Not with one click, but it is small work. You create the shared mailbox, give the right people access and switch the address over. Mail that is already in personal inboxes does not move with it. That is rarely a problem: from the switch onwards, everything sits in one place.
In Microsoft 365 management we go through addresses like these at the start. It is often the first change an office notices.