How to set up a shared inbox in Outlook, and when your team outgrows it

Adding an existing shared mailbox in new Outlook and Outlook on the web

This is for a shared mailbox someone else already created and gave you access to. The steps are close to identical in new Outlook (Windows) and Outlook on the web, since both share the same interface.

1. 1

   In the folder pane on the left, find your account name or the Folders heading and right-click it.

   [SCREENSHOT: Right-click menu on the account name in the new Outlook folder pane]
2. 2

   Choose "Add shared folder or mailbox" (new Outlook) or "Add shared folder" (Outlook on the web) from the menu.

   [SCREENSHOT: Menu item reading Add shared folder or mailbox]
3. 3

   Type the email address of the shared mailbox and select it once it appears in the results.

   [SCREENSHOT: Search field with a shared mailbox address entered and matched]
4. 4

   Select Add. The shared mailbox appears as its own expandable entry in the folder pane, below your personal mailbox.

   [SCREENSHOT: Shared mailbox listed as a separate expandable folder in the left pane]
5. 5

   Expand it to see its Inbox, Sent Items, and other folders, and open any message the same way you would in your own mailbox.

Adding a shared mailbox in classic Outlook

Classic (desktop) Outlook handles this a little differently, and the exact wording of the dialogs has shifted across versions, so treat the settings area as the reliable landmark rather than the precise label on a button.

1. 1

   Check the folder pane first: if someone has already granted you Full Access permission to the mailbox, it can appear there automatically the next time Outlook restarts, with nothing else to configure.

2. 2

   If it hasn't appeared, go to File, then Account Settings, then Account Settings again.

   [SCREENSHOT: Outlook File menu with Account Settings highlighted]
3. 3

   On the Email tab, select your own account, then open the account's advanced or "More Settings" options.

4. 4

   Open the Advanced tab in that dialog and select Add.

   [SCREENSHOT: Advanced tab of the account settings dialog with an Add button]
5. 5

   Enter the shared mailbox's name or email address and confirm.

6. 6

   Select OK, close the dialogs, then restart Outlook so the shared mailbox loads into the folder pane.

Creating a shared mailbox as a Microsoft 365 admin

This is the step before either of the above: someone with admin rights has to create the shared mailbox before anyone can add it to their own Outlook. It's done in the Microsoft 365 admin center, not inside Outlook itself.

1. 1

   Sign in to the Microsoft 365 admin center with an account that has Global Administrator or Exchange Administrator rights.

2. 2

   In the admin center's navigation, find the shared mailboxes area (it lives under the Teams & groups section in most tenants, sometimes as its own "Shared mailboxes" entry).

   [SCREENSHOT: Microsoft 365 admin center left navigation with Shared mailboxes highlighted]
3. 3

   Select the option to add a shared mailbox, then give it a name and an email address.

   [SCREENSHOT: Add a shared mailbox dialog with name and email fields]
4. 4

   Save it, then add the people who should have access as members, so they can open and send from it without a separate sign-in.

5. 5

   Allow a short time for it to provision, then each member can add it in Outlook using the steps above for their version.

Where Outlook shared mailboxes hit a wall

None of the above changes what a shared mailbox fundamentally is: one Exchange mailbox several people can open. That works well for reading mail together, and starts to strain once a team is actually working messages, not just viewing them.

• No assignment: everyone sees the same inbox with no owner field, so nothing marks a message as somebody's responsibility.
• No collision detection: nothing warns a second person that a message is already being answered, so two people can end up drafting the same reply at once.
• No ownership or status: there's no built-in way to mark a message as in progress or done, short of an ad hoc convention like colored categories or manual flags that only work if everyone follows them.
• Forwarding fragility: rules that forward or route mail into a shared mailbox are easy to misconfigure, and a broken rule tends to fail silently, so messages go missing without anyone noticing until a customer follows up.

When your team has outgrown a shared mailbox

Once messages regularly turn into engineering work, and especially once more than a couple of people are working the same inbox, the gaps above stop being minor annoyances and start costing dropped replies and duplicated effort. That's the point to look at a purpose-built shared inbox for engineering teams, which adds the ownership, assignment, and a one-keystroke path to Linear that an Outlook shared mailbox was never built for, without asking anyone to give up the inbox they already check every day.