How to Add a Shared Mailbox in Outlook (Windows, Mac, Web and Mobile)

Applies to: Microsoft 365 work or school accounts in classic Outlook, new Outlook for Windows, Outlook on the web, Outlook for Mac and the Outlook mobile app. Shared mailboxes are an Exchange feature, so they don’t work with Outlook.com, Gmail or other personal accounts.

Before you start: you need access

A shared mailbox is an address such as [email protected] or [email protected] that several people read and answer. It has no password of its own. You open it with your own work account, and that only works after an admin gives you permission.

• Full Access (shown as “Read and manage”) lets you open the mailbox and read, move and delete its mail.
• Send As lets you send mail that appears to come straight from the shared address.
• Send on Behalf lets you send mail shown as “You on behalf of Support”.

If you try the steps below without Full Access, Outlook shows an error such as “Cannot expand the folder”. Ask your IT team or Microsoft 365 admin to add you first (the admin steps are further down).

Add a shared mailbox in classic Outlook for Windows

Usually it adds itself. When an admin gives you Full Access in Microsoft 365, the mailbox is normally set to automap: it appears in your folder list under its own name the next time Outlook starts. Close and reopen Outlook. Permission changes can take a while to reach your account, so if it isn’t there yet, try again later.

If it still doesn’t show (for example, because your admin turned automapping off), add it by hand:

1. Select File > Account Settings > Account Settings.
2. On the Email tab, select your work account and click Change.
3. Click More Settings and open the Advanced tab.
4. Under Open these additional mailboxes, click Add, type the shared mailbox name or address and click OK.
5. Click Apply, OK, then Next and Done. Close the Account Settings window.

The shared mailbox now appears below your own mailbox in the folder pane. Don’t use File > Add Account with a password for a shared mailbox: it has no password to sign in with, and adding it this way just repeats the access you already have.

Add a shared mailbox in new Outlook for Windows

The new Outlook app doesn’t use the Account Settings window above.

1. In the folder pane, find Shared with me (below your own folders). If you don’t see it, right-click your account name instead.
2. Right-click and choose Add shared folder or mailbox.
3. Type the shared mailbox name or address, pick it from the suggestions and select Add.

The mailbox appears under Shared with me. Mailboxes you add here also show in Outlook on the web, because both use the same settings.

Add a shared mailbox in Outlook on the web

Sign in at outlook.office.com with your work account. You have two options:

• Show it with your folders: right-click Folders (or your name) in the left pane, choose Add shared folder or mailbox, type the address and select Add.
• Open it in its own tab: select your profile picture at the top right, choose Open another mailbox, type the address and select Open. This gives the shared mailbox its own full view, which is handy if you work in it all day.

Add a shared mailbox in Outlook for Mac

Automapping doesn’t apply on a Mac, so you always add the mailbox yourself.

1. Select Outlook > Settings (or Tools > Accounts) and open Accounts.
2. Select your work account, then Delegation and Sharing.
3. On the Shared With Me tab, click +, search for the shared mailbox and click Add.

Menu names vary a little between the new and legacy Outlook for Mac, but the Delegation and Sharing section is where shared mailboxes live in both.

Add a shared mailbox on iPhone or Android

1. Open the Outlook app and make sure your work account is already added.
2. Tap your profile picture or the account icon, then tap + (Add account).
3. Choose Add a shared mailbox, select your work account if asked, type the shared address and tap Add.

The shared mailbox then shows as its own account in the app’s account list. The built-in iPhone Mail and Android Gmail apps can’t open Microsoft 365 shared mailboxes.

Send email from the shared mailbox

Reading a shared mailbox and sending from it are separate permissions. If you have Send As or Send on Behalf:

1. Start a new email.
2. If you don’t see a From field, turn it on: in classic Outlook select Options > From; in new Outlook and on the web select Options (or the three dots) > Show From.
3. Click From and pick the shared address. If it isn’t listed, choose Other email address and type it.
4. Write and send as normal.

When you reply to a message inside the shared mailbox’s own Inbox, Outlook usually fills in the shared address for you.

By default, mail you send from the shared address is saved in your Sent Items, not the shared mailbox’s. Admins can change that so the team sees all sent replies (see the PowerShell command below).

For admins: give someone access

In the Microsoft 365 admin center, go to Teams & groups > Shared mailboxes, select the mailbox and edit Members under “Read and manage”. You can also open the Exchange admin center, go to Recipients > Mailboxes, select the shared mailbox and use Delegation to set Read and manage (Full Access), Send as and Send on behalf.

Useful Exchange Online PowerShell commands:

# Full Access without automapping (user adds it by hand)
Add-MailboxPermission -Identity [email protected] -User [email protected] -AccessRights FullAccess -AutoMapping $false

# Keep a copy of mail sent as the shared address in the shared Sent Items
Set-Mailbox -Identity [email protected] -MessageCopyForSentAsEnabled $true -MessageCopyForSendOnBehalfEnabled $true

Turning automapping off is worth it for people with access to many shared mailboxes, because each automapped mailbox makes classic Outlook slower to start. A shared mailbox doesn’t need its own license while it stays under 50 GB and nobody signs in to it directly.

Shared mailbox not showing or not working

What you see	What to try
Mailbox doesn’t appear after you were given access	Restart Outlook and wait, because permissions can take time to apply. Then add it by hand (steps above).
“Cannot expand the folder” or “The set of folders cannot be opened”	You don’t have Full Access yet, or the address is wrong. Check with your admin.
Mailbox appears twice in classic Outlook	It’s automapped and also added under Advanced. Remove it from the Advanced tab list.
New mail in the shared mailbox is slow to show	In classic Outlook, go to More Settings > Advanced and try turning Download shared folders off or on, then restart Outlook.
You can read mail but sending fails	You have Full Access but not Send As or Send on Behalf. Ask the admin to add it.
Mailbox still shows after your access was removed	Remove it from the Advanced tab (classic) or right-click it and choose Remove (new Outlook and web), then restart.

Frequently asked questions

Do I need a password for a shared mailbox?

No. You open a shared mailbox with your own work account once you have permission. Shared mailboxes don’t have their own sign-in.

Can I add a shared mailbox to Outlook.com or Gmail?

No. Shared mailboxes are part of Microsoft Exchange and Microsoft 365. A personal Outlook.com or Gmail account can’t open them, though you can forward mail from a shared mailbox if your admin allows it.

Why can’t I search the shared mailbox?

In classic Outlook, search on an added mailbox can be limited when shared folders are cached. Open the mailbox in Outlook on the web (Open another mailbox) for a full server-side search.

How do I remove a shared mailbox from Outlook?

In classic Outlook, remove it from the Advanced tab list. If it was automapped, it only goes away when the admin removes your access or re-adds you with automapping off. In new Outlook and on the web, right-click the mailbox and choose Remove.

Having trouble with Outlook itself? See our other guides in Office & Outlook.