How to Add a Shared Mailbox in Outlook (New, Classic, Web and Mobile)

To add a shared mailbox in Outlook, right-click your account name in the folder pane (new Outlook) or Folders (Outlook on the web), choose Add shared folder or mailbox, type the mailbox address, such as [email protected], and select Add. In classic Outlook for Windows, the shared mailbox usually appears on its own after your admin gives you access and you restart Outlook. If it doesn't, add it under File → Account Settings → Account Settings → Change → More Settings → Advanced → Add.

One thing has to happen first: a Microsoft 365 admin must give you permission to the mailbox. You never sign in to a shared mailbox with its own password; you open it from your own work account.

What a shared mailbox is (and what you need first)

A shared mailbox is one Exchange mailbox, like info@ or support@, that several people in your organization read and send from. It has its own Inbox, Sent Items and calendar, but nobody signs in to it directly.

Access comes from three permissions your admin sets:

• Full Access lets you open the mailbox, read, move and delete mail, and use its calendar. On its own, it doesn't let you send.
• Send As lets you send mail that looks like it came from the shared mailbox itself (recipients see "Support").
• Send on Behalf lets you send mail that shows as "Alex Morgan on behalf of Support".

If you need access, ask your IT admin for Full Access plus Send As. Only people inside your organization, with their own licensed mailbox, can use it.

Add a shared mailbox in classic Outlook for Windows

Automatically (automapping)

When an admin grants you Full Access directly, Exchange uses automapping: restart classic Outlook and the shared mailbox appears in the folder pane below your own. Automapping doesn't work when access is given through a security group, and admins can turn it off per person. In those cases, add the mailbox manually.

Manually

1. Go to File → Account Settings → Account Settings.
2. On the Email tab, select your own account and click Change.
3. Click More Settings, then open the Advanced tab.
4. Under Open these additional mailboxes, click Add.
5. Type the shared mailbox's address (for example [email protected]) and click OK, then OK again.
6. Click Next, then Finish, then Close.

The mailbox shows up in the folder pane, below your own mailbox.

Add a shared mailbox in new Outlook for Windows

New Outlook often adds shared mailboxes you have access to by itself. Close and restart new Outlook, then look for a Shared with me folder in the folder pane. If the mailbox isn't there:

1. Select Mail in the left navigation bar.
2. In the folder pane, right-click your account name.
3. Select Add shared folder or mailbox.
4. Type the shared mailbox's email address, pick it from the suggestions, and select Add.

Expand Shared with me to see the shared mailbox with its own Inbox, Drafts and Sent Items. It can take a few minutes after you're given access before it appears, so wait and restart again if needed.

To remove it later, right-click the shared mailbox and choose Remove shared folder.

Add a shared mailbox in Outlook on the web

Outlook on the web (outlook.office.com) doesn't add shared mailboxes for you. Pick one of two options.

Show it in your folder list:

1. Right-click Folders in the folder pane (with an on-premises Exchange server, right-click your mailbox name instead).
2. Select Add shared folder or mailbox.
3. Type the shared mailbox's address and select Add.

Open it in its own browser tab:

1. Select your profile picture in the top-right corner.
2. Select Open another mailbox.
3. Type the shared mailbox's address and select Open.

The second option suits people who watch the mailbox all day: it opens in its own tab and gives you new-message notifications, which the folder-list version doesn't.

Add a shared mailbox in Outlook for Mac

In new Outlook for Mac:

1. Go to Tools → Accounts and select the account that has access.
2. Select Delegation and Sharing, then the Shared With Me tab.
3. Click +, find the shared mailbox, and add it.

You can also use File → Open → Shared Mailbox. In legacy Outlook for Mac, shared mailboxes are added under Tools → Accounts → Advanced → Delegates, in the Open these additional mailboxes list.

Add a shared mailbox on iPhone or Android

The Outlook mobile app supports shared mailboxes if both your mailbox and the shared one are in Exchange Online:

1. Open Outlook and tap your profile picture to open the account list.
2. Tap the add account button.
3. Tap Add a shared mailbox.
4. If you have several accounts in the app, pick the one that has access.

The shared mailbox then appears as its own account. To remove it, go to Settings → Accounts, tap it, and choose Delete Account.

Send email from the shared mailbox

Opening a shared mailbox and sending from it are separate permissions. To send as Support:

1. Start a New mail (or reply to a message in the shared Inbox).
2. If there's no From field, turn it on: in new Outlook go to Options → Show From; in classic Outlook click Options → From; on the web select … (More actions) in the message and choose Show From.
3. Click From and choose the shared address. If it isn't listed, choose Other email address and type it.
4. Write your message and click Send.

When replying inside the shared mailbox, check From before you send, so you don't answer a customer from your personal address.

Where sent messages are saved

By default, an email you send from the shared address can land in your own Sent Items, so teammates don't see the reply. The fix is on the server and works in every Outlook version: an admin opens the shared mailbox in the Microsoft 365 admin center, selects Edit under Sent items, and turns on Copy items sent as this mailbox and Copy items sent on behalf of this mailbox. From then on, a copy lands in the shared mailbox's own Sent Items too. (In PowerShell, it's Set-Mailbox -MessageCopyForSentAsEnabled $true -MessageCopyForSendOnBehalfEnabled $true.)

For admins: create a shared mailbox in Microsoft 365

1. Sign in to the Microsoft 365 admin center with an Exchange admin role.
2. Go to Teams & groups → Shared mailboxes (select Show all if you don't see Teams & groups).
3. Select + Add a shared mailbox, enter a name (the email address fills in from it), and select Save changes.
4. Under Next steps, select Add members to this mailbox, then Add members, choose the people, and select Add.

Sign-in is blocked by default; leave it that way. To grant Full Access or Send As individually, use the Exchange admin center: Recipients → Mailboxes, select the mailbox, then Manage mailbox delegation. Grant permissions to people directly, not through a security group, if you want automapping.

Why your shared mailbox isn't showing up (or won't send)

The permission isn't there yet. New permissions take time to reach every server. Restart Outlook after a few minutes; for a brand-new mailbox, Microsoft says replication can take about an hour.

Automapping didn't kick in. It only works when access is granted to your account directly, not through a security group, and an admin can turn it off per person. Add the mailbox manually from the Advanced tab (classic) or with Add shared folder or mailbox (new Outlook and web).

You're looking in the wrong place. In new Outlook and on the web, scroll to Shared with me or the bottom of the folder list and expand it.

Folders look empty or out of date in classic Outlook. In Cached Exchange Mode, check File → Account Settings → Account Settings → Change → More Settings → Advanced and make sure Download shared folders is ticked. Then restart Outlook and give it time to sync.

"You do not have the permission to send the message on behalf of the specified user." You have Full Access but not Send As or Send on Behalf, or the permission hasn't replicated yet. Wait an hour; if it still fails, ask your admin for Send As. In classic Outlook, also try From → Other email address and pick the shared mailbox from the address book instead of typing it, because a stale autocomplete entry can cause the same error.

You can't remove an automapped mailbox. A mailbox that classic Outlook added automatically isn't listed on the Advanced tab, so you can't remove it there. Your admin has to remove your access, or reapply it with automapping turned off.

Frequently Asked Questions

Do I need a password to add a shared mailbox? No. You open it with your own Microsoft 365 account once an admin has given you access.

How long does it take for a shared mailbox to appear in Outlook? Usually a few minutes after access is granted, plus a restart of Outlook. New permissions can take up to an hour to replicate.

Why can I read the shared mailbox but not send from it? Full Access lets you read and manage mail only. Sending needs a separate Send As or Send on Behalf permission.

How many people can use a shared mailbox? Microsoft lists a maximum of 25 users for a shared mailbox. For larger teams, it recommends a Microsoft 365 group instead.

Does a shared mailbox need a license? Not up to 50 GB. It needs one (such as Exchange Online Plan 2) for more storage, a larger archive or litigation hold. Everyone who opens it needs their own licensed mailbox.

Catch up on a busy shared inbox faster

Shared mailboxes collect long threads: a customer issue three teammates replied to over a week, or a conversation you're joining halfway through. CoreGPT for Outlook summarizes a whole thread in a few lines, right next to the message, so you see what was asked, promised and still open before you reply from the shared address. It's free to start.

Try it: CoreGPT for Outlook

Related reading:

• How to Share Your Outlook Calendar (and Choose What People Can See)
• New Outlook vs Classic Outlook: What Changed and What to Do
• Outlook Not Receiving Emails? 13 Fixes, From Most to Least Likely