How to Open a Shared Mailbox in Outlook
A shared mailbox lets multiple people read and send email from a single address — common for team inboxes like [email protected] or [email protected]. Opening one in Outlook is straightforward once you understand the two main methods and what affects which one applies to your situation.
What Is a Shared Mailbox?
A shared mailbox is a mailbox in Microsoft 365 (formerly Office 365) or Exchange that isn't tied to a single user account. Instead, it's granted to a group of users through delegate access permissions assigned by an IT administrator. Users access it using their own credentials — there's no separate login for the shared mailbox itself.
Because of this structure, you can only open a shared mailbox if your admin has already granted you permission. If access has been granted, Outlook can display it in two ways: automatically (it just appears in your folder list) or manually (you add it yourself).
Method 1: The Shared Mailbox Appears Automatically
In many Microsoft 365 environments, once an admin grants you Full Access permission to a shared mailbox, Outlook adds it to your folder list automatically within a few minutes to an hour — no action needed on your part.
Look in the left-hand folder pane of Outlook. Below your primary mailbox folders, you should see the shared mailbox listed by name, with its own Inbox, Sent Items, and other folders nested underneath.
If this hasn't happened after a reasonable wait, a full close and restart of Outlook often triggers it to load. In some cases, signing out of Outlook and back in also resolves a delay.
Method 2: Manually Adding a Shared Mailbox in Outlook for Windows 🖥️
If the mailbox doesn't appear automatically, you can add it manually through account settings.
- Open Outlook and go to File in the top-left corner.
- Under your account, click Account Settings, then select Account Settings again from the dropdown.
- In the Email tab, select your primary Microsoft 365 or Exchange account and click Change.
- Click More Settings in the window that opens.
- Go to the Advanced tab and click Add.
- Type the name or email address of the shared mailbox and click OK.
- Close and finish — the shared mailbox will now appear in your folder list.
This approach works with the classic Outlook desktop client connected to an Exchange or Microsoft 365 account. It requires that delegate access has already been configured by your administrator.
Opening a Shared Mailbox in Outlook on the Web 🌐
If you're using Outlook on the Web (formerly OWA, accessed via browser), the process is different:
- Right-click on your primary mailbox name in the left sidebar.
- Select Add shared folder or mailbox.
- Search for and select the shared mailbox by name or email address.
- Click Add — it will appear in your folder list below your own mailbox.
This method is often faster and doesn't require restarting anything.
Shared Mailbox Access in the New Outlook and Outlook for Mac
New Outlook for Windows (the updated version Microsoft is rolling out) handles shared mailboxes similarly to Outlook on the Web. You can right-click your account name in the folder pane and look for an option to add a shared mailbox or shared folder.
Outlook for Mac follows a comparable path: right-click your primary account in the sidebar, select Open Shared Mailbox, and enter the mailbox address.
The exact wording of menu options varies slightly depending on the version of Outlook you're running and whether your organization uses classic Exchange, Microsoft 365, or a hybrid setup.
Key Variables That Affect Your Experience
| Factor | Why It Matters |
|---|---|
| Outlook version | Classic desktop, New Outlook, Mac, and web all have different menus |
| Account type | Only Exchange/Microsoft 365 accounts support shared mailboxes natively |
| Admin permissions | Full Access must be granted before any method will work |
| Auto-mapping setting | Admins can enable or disable automatic mailbox mapping |
| Sync delay | Permission changes can take time to propagate across Microsoft's systems |
When the Shared Mailbox Isn't Showing Up
If you've been told you have access but can't see the mailbox:
- Restart Outlook — permission sync delays are common.
- Check with your IT admin — confirm Full Access (not just Send As) was granted.
- Try the manual method — auto-mapping can be disabled at the admin level.
- Use Outlook on the Web — it often reflects permission changes faster than the desktop client.
- Check your account type — if you're connecting via POP or IMAP rather than Exchange/Microsoft 365, shared mailbox access isn't available through those protocols.
Sending Email From a Shared Mailbox
Once the mailbox is open, sending email as that address requires a separate permission called Send As (or sometimes Send on Behalf of). These are distinct from Full Access and need to be configured separately by your admin. In Outlook, you'd use the From field dropdown when composing a message to switch the sending address — but this field only appears when multiple send-from addresses are available.
Whether the process takes seconds or requires a few troubleshooting steps depends heavily on your specific Outlook version, how your organization's Exchange environment is configured, and exactly which permissions your admin has set up for your account.