Shared mailbox, distribution list, or Microsoft 365 group: which one should info@ be?
Short answer: if several people need to read and reply to the same mail from one address, make info@ a shared mailbox. If you only need one address that sends a copy to several inboxes, use a distribution list. Use a Microsoft 365 group when the same team also needs shared files, a calendar and a Teams channel, and you are willing to take on the extra parts that come with it.
All three give you an address, and all three can be set up so your team replies from it. They differ in where the email actually lives once it arrives, and that difference decides everything else.
The three, side by side
| Shared mailbox | Distribution list | Microsoft 365 group | |
|---|---|---|---|
| Where the mail lives | One mailbox everyone opens | A copy in each member's own inbox | A group mailbox, optionally copied to members |
| License | None, up to 50 GB | None | None for the group; members need their own |
| Can you sign in to it? | No | No, it is not a mailbox | No |
| Send from the address | Yes, with Send As | Yes, with Send As | Yes, with Send As |
| Everyone sees replies | Yes | No, unless copied in | Yes, in the group conversation |
| Read or unread | Shared: one person opens it, it is read for all | Per person | Per person |
| Comes with | Nothing else | Nothing else | A SharePoint site and calendar; can be connected to Planner and Teams |
| Who owns each email | Nobody | Nobody | Nobody |
Shared mailbox: one inbox, everyone opens it
A shared mailbox is a real Exchange Online mailbox with no user of its own. Nobody signs in to it. You grant people Full Access and Send As permissions, and it appears in their Outlook next to their own mailbox.
Where the mail lives: in the shared mailbox, once. Everyone with access sees the same folders, the same messages, the same read state.
Cost: no separate license is required up to 50 GB. A license is needed for larger storage, and for some advanced features. Raising the mailbox itself to 100 GB requires an Exchange Online Plan 2 license.
How to create one: Microsoft 365 admin center, then Teams & groups, then Shared mailboxes, then Add a shared mailbox. Give it a name and the address, then add the members.
It can take up to an hour to appear in members' Outlook. If it has not shown up after that, restarting Outlook usually does it.
The gotcha everyone hits: by default, a reply sent from the shared address is saved only in the sender's own Sent Items, not the shared mailbox's. So the next person to open the thread has no way of seeing that a reply already went out. It is fixable, and you should fix it on day one. In the Exchange admin center, open the shared mailbox, find the Sent items section, and turn on both "Copy items sent as this mailbox" and "Copy items sent on behalf of this mailbox".
Or in Exchange Online PowerShell:
Set-Mailbox info@yourdomain.com -MessageCopyForSentAsEnabled $true -MessageCopyForSendOnBehalfEnabled $trueThe other gotcha, and this one has no setting to fix it: read state is shared. Open a message and it stops being bold for everybody. Read is not the same as handled. Ten minutes later nobody can tell whether that email was dealt with, or whether somebody glanced at it on their phone and moved on.
Distribution list: one address, a copy for everyone
A distribution list is not a mailbox. It is an address that puts a copy of each message into every member's own inbox, and then it is done.
Where the mail lives: in five places if there are five members. There is no shared copy, no shared folders, no single record.
Cost: nothing.
How to create one: admin center, then Teams & groups, then Active teams & groups, then the Distribution lists tab, then Add a distribution list. Add the members. If customers will write to it, allow people outside your organization to send to it, which is off by default.
What it is good for: announcements, alerts, system notifications, anything where the point is that everyone gets a copy and nobody needs to act on it together.
What it is bad for: exactly the thing most businesses use it for. Five people get the inquiry. Two reply within the hour, so the customer hears from two different strangers. Or all five assume one of the others has it, and nobody replies at all. Everyone receives a copy, and there is no shared state anywhere showing what the team did with it, so nothing tells anyone which of those two things just happened.
Microsoft 365 group: a group mailbox plus everything else
A Microsoft 365 group combines a group mailbox with the rest of Microsoft 365's collaboration tools: it has its own mailbox, a SharePoint site and a shared calendar, and it can be connected to Planner, Teams and other services.
Where the mail lives: in the group mailbox, as a threaded conversation every member can read in the Groups section of Outlook. Members can also choose to follow the group in their own inbox and receive a copy of each message.
Cost: nothing for the group itself. Members need their own Microsoft 365 license, which they already have.
How to create one: admin center, then Teams & groups, then Active teams & groups, then Add a Microsoft 365 group.
Two settings to check before you point info@ at it. First, allow external senders, which is off by default, so customers can actually reach it. Second, decide whether members are subscribed, so mail lands in their inbox rather than only in the group view where it is easy to forget.
What you get that a shared mailbox lacks: conversation threading, per-person read state, and the files and calendar around the team.
What you take on: a SharePoint site you may never open, a group expiration policy that can delete the group if nobody renews it, and members who see the conversation view behaving differently from those who receive copies. For a plain info@ address, most of that is overhead.
Which one, then
- Notifications and announcements only: distribution list.
- A working inbox for a small team: shared mailbox. Turn the sent items copy on the day you create it.
- A team that already lives in Teams and SharePoint: Microsoft 365 group.
If you are unsure, start with a shared mailbox. It is the simplest to reason about and the easiest to change later.
The thing none of them does
All three deliver the email. None of them is, on its own, an ownership system.
A shared mailbox marks a message read the moment anyone looks at it, and read is not the same as handled. A distribution list gives five people a copy and keeps no record of who replied. A group gives everyone the conversation and assigns it to nobody. You can paper over this with categories, flags and rules, and plenty of teams do, but that is a habit somebody has to maintain rather than something the mailbox does for you.
So the question none of them answers by itself is the one that matters at five on a Friday: who owns this email, and has anyone actually dealt with it?
That is the gap InboxAgent fills. It reads the mailbox you already have, works out which emails are sales leads, and puts a name against each one so you can see it. It never sends anything. Here is how it works.