How to Add a Shared Mailbox in Outlook (Desktop, Web & Mobile)

A shared mailbox lets multiple people read, send, and manage email from a single address — like [email protected] or [email protected] — without needing separate login credentials for each user. If your IT admin has granted you access, adding that mailbox to Outlook is usually straightforward. How you do it, though, depends on which version of Outlook you're using and how your organization's email is set up.

What Is a Shared Mailbox, Exactly?

A shared mailbox is a special type of mailbox in Microsoft Exchange or Microsoft 365 that isn't tied to a single user account. Instead, it's a resource that administrators can grant access to — called Full Access permission — for one or more people on a team.

When you have Full Access, you can:

• Read and send emails on behalf of the shared address
• Manage folders, subfolders, and calendar items within it
• Set up rules and auto-replies if given delegate rights

You do not log into a shared mailbox with its own password. You access it through your own Outlook account, once permissions are in place on the server side.

📌 Important: If you haven't been granted access by your IT administrator, Outlook won't be able to add the mailbox regardless of which method you try. Always confirm permissions first.

How to Add a Shared Mailbox in Outlook for Windows (Classic Desktop App)

In most Microsoft 365 and Exchange environments, Outlook for Windows automatically detects shared mailboxes you've been granted access to and adds them within a few minutes — sometimes after restarting the app.

If it doesn't appear automatically:

1. Open Outlook and go to File → Account Settings → Account Settings
2. Select your email account and click Change
3. Click More Settings → Advanced tab
4. Under Open these additional mailboxes, click Add
5. Type the shared mailbox address and click OK
6. Click Apply, then Next, then Finish

The shared mailbox will appear in the left-hand folder pane beneath your primary inbox.

How to Add a Shared Mailbox in Outlook on the Web (OWA)

Outlook on the Web — accessed through outlook.office.com or your organization's Microsoft 365 portal — handles shared mailboxes slightly differently.

Option 1: Open it as a separate mailbox

1. Right-click Folders in the left navigation pane
2. Select Add shared folder or mailbox
3. Search for the shared mailbox name or email address
4. Click Add

The shared mailbox appears as a secondary folder group in your sidebar.

Option 2: Switch into the mailbox directly If you need to work extensively from the shared mailbox, you can open it in a separate browser tab:

• Navigate to outlook.office.com/mail/ and add ?
• Or use the account switcher (your profile photo, top-right corner) to open the shared mailbox as its own view

This gives you a clean, dedicated interface for the shared address — useful for teams managing high-volume inboxes.

How to Add a Shared Mailbox in Outlook for Mac

The Mac version of Outlook behaves similarly to the Windows desktop app, but the menu paths differ slightly:

1. Open Outlook and go to Tools → Accounts
2. Select your Microsoft 365 or Exchange account
3. Click Advanced → Delegates
4. Under People I am a delegate for, click +
5. Search for and add the shared mailbox

Alternatively, shared mailboxes your admin has configured may appear automatically after a sync cycle.

How to Access a Shared Mailbox in Outlook Mobile (iOS & Android)

The Outlook mobile app doesn't support adding shared mailboxes as a persistent, separate folder in the same way desktop clients do. Instead, you can:

• Switch accounts if the shared mailbox has been set up as its own account by your admin
• Access it through the Outlook on the Web mobile browser experience
• Use delegate access if your admin has set that up specifically for mobile

This is one area where the experience varies significantly depending on your organization's configuration and which version of the mobile app you're running.

Key Variables That Affect How This Works 🔧

Not every shared mailbox setup behaves the same way. Several factors shape what you'll see:

Auto-mapping is worth understanding specifically. When an admin grants Full Access permissions in Microsoft 365, Outlook for Windows will often add the shared mailbox automatically through a feature called auto-mapping. Some admins disable this intentionally — in which case you'll need to add it manually using the steps above. If the mailbox isn't appearing and you're confident you have access, this is usually why.

When Sending From a Shared Mailbox

Once the mailbox is added, you can compose emails and send from the shared address. In Outlook for Windows and OWA, a From field appears in the compose window — click it to switch between your personal address and the shared one.

Whether you appear as "Sender Name on behalf of Shared Mailbox" or simply as the shared mailbox address depends on whether you have Send As or Send on Behalf permission — a distinction your IT admin controls at the server level.

The Part That Depends on Your Setup

The steps above cover the most common scenarios, but shared mailbox behavior is one of those areas where small differences in environment add up quickly. Whether the mailbox appears automatically or needs to be added manually, whether mobile access works seamlessly, and how sent emails are attributed — all of it comes down to the specific combination of your Outlook version, your organization's Exchange or Microsoft 365 configuration, and the exact permissions your admin has assigned to your account.