How to Add a Shared Mailbox to Outlook on Any Device

To add a shared mailbox in Outlook, first ask your Microsoft 365 or Exchange administrator to grant your work or school account access, then add the mailbox from Outlook’s account or folder settings. Once it appears, you can read and organize its messages; sending from it may require separate permission. The exact menu depends on whether you use new Outlook, classic Outlook, Outlook for Mac, the web, or a phone.

What You’ll Need

A work or school Microsoft 365 or Exchange account. Shared mailboxes are usually provided by an organization, not set up as an ordinary personal Outlook.com mailbox.
The shared mailbox’s email address. For example, support@contoso.com. Ask the mailbox owner or your IT team if you do not know it.
Permission to access the mailbox. An administrator or mailbox owner must grant your account access. If you need to send messages as the shared address, request the appropriate Send As or Send on Behalf permission too.
An internet connection and an up-to-date Outlook app. Some Outlook versions show a mailbox automatically after permission is granted; other versions let you add it manually.

Step-by-Step

Confirm access before changing Outlook settings. Contact your organization’s IT team or the person responsible for the mailbox. Give them your work account and the shared mailbox address, and explain whether you only need to read and manage messages or also send from the address. Full Access lets you open and manage the mailbox, but does not by itself grant permission to send as it. Send As and Send on Behalf are separate permissions. Wait for the access change to take effect; it can take some time to appear across Microsoft 365 services.
Check whether Outlook has already added the mailbox. Close and reopen Outlook, then look in the folder pane below your primary account for the shared address or its display name. In Outlook on the web, expand the folders list and check for it there. Microsoft 365 can automatically map a mailbox to Outlook for Windows when an administrator grants Full Access. If it is already listed, expand it rather than adding it a second time. Automatic mapping may not happen immediately, and it is not available in every account setup.
Add it in new Outlook for Windows. Open Outlook and look in the folder pane. Right-click your account name or the Shared with me heading, then choose Add shared folder or mailbox. If you do not see that option, open Settings (the gear) and go to Accounts > Shared with me; select Add or the equivalent add-mailbox control. Type the shared mailbox’s email address, choose the matching result if Outlook offers one, and confirm. The mailbox should appear in the folder pane. Expand its name to see folders such as Inbox, Sent Items, and Drafts. Labels can vary slightly as Microsoft updates Outlook.
Add it in classic Outlook for Windows if it is not mapped automatically. Select File > Account Settings > Account Settings. On the Email tab, select your work or school account and choose Change. Select More Settings, open the Advanced tab, and choose Add under Open these additional mailboxes. Enter the shared mailbox address or name, select OK, then select Next and Finish if those buttons appear. Close and reopen Outlook. The mailbox should show in the folder pane beneath your account. Do not enter the shared mailbox as a separate account or use another person’s password.
Open it in Outlook for Mac. In current Outlook for Mac, use File > Open > Shared Mailbox, enter the mailbox address, and confirm. If that command is not available in your version, check Tools > Accounts, select your work account, and look for Delegation and Sharing or Shared With Me; use the add control there if present. In older builds, the wording and location can differ, so update Outlook or ask your administrator which build your organization supports. When added, expand the mailbox in the folder list.
Add it in Outlook on the web. Sign in to Microsoft 365 or Outlook on the web with the account that has permission. In the folder pane, right-click Folders or your folder list, choose Add shared folder or mailbox, enter the address, and select Add. If the folder pane is collapsed, open it first using the navigation control at the upper-left. The mailbox is added to your folder list, where you can expand it and open its folders. If your organization uses a customized web portal, the wording may be slightly different.
Use the mailbox and check the From address before sending. Select its Inbox to read or reply to messages. To start a new message from the shared address, create a message and show the From field if it is hidden; in classic Outlook for Windows, use Options > From. Select the field, choose the shared address, or enter it if Outlook allows. If it is not available, ask IT to check your Send As or Send on Behalf permission. Send a brief test only when appropriate for your organization. Replies may use your own address if you compose from your personal Inbox, so start the message from the shared mailbox or explicitly check From.

On Outlook for iOS or Android: Open Outlook, tap your profile picture or account icon, then use the add-account control and choose Add Shared Mailbox if shown. Select the account that has access, enter the shared address, and confirm. Mobile menu labels vary by app version and organization. If the option is missing, update the app or use Outlook on the web or a computer to add the mailbox first.

Common Mistakes

Trying to add it before access is granted. Knowing the address is not enough. Outlook cannot open a mailbox your account has not been authorized to use.
Adding it as a separate signed-in account. A shared mailbox normally does not have a separate password for each user. Add it from your own work account; never ask for or use a coworker’s credentials.
Assuming reading permission includes sending permission. Full Access and send permissions are distinct. You may be able to read messages but receive a rejection when sending from the shared address.
Adding duplicates while waiting for automatic mapping. If it is already in the folder pane, do not add it again. Duplicate entries can make it unclear which Inbox or Sent Items folder you are using.
Composing from the wrong mailbox. A message can look like it is for the shared mailbox while its From address is still your personal work account. Verify the From field before sending.
Expecting changes to appear instantly or identically everywhere. Permission updates, synchronization, and available controls vary by Outlook version and organization settings. Give changes time to sync and check another supported Outlook client if needed.

Tips

Ask for the minimum permissions you need. Request Full Access to read and manage the mailbox, and ask separately for Send As or Send on Behalf only if your role requires sending. Your organization may use a group to manage access.
Use a clear display name. If several team mailboxes look alike, ask the owner to confirm the correct address before adding it. You can often tell them apart by the mailbox name shown in the folder pane.
Keep work organized. Expand only the shared mailbox folders you use regularly. If you handle several shared mailboxes, note which address you are replying from and review the recipient and From fields before sending sensitive or customer-facing messages.
Allow time for permission changes. After IT grants access, sign out and back in only if requested, or close and reopen Outlook. Avoid repeatedly removing and re-adding the mailbox while the change is still propagating.
Use the web version to compare. If the mailbox works in Outlook on the web but not in the desktop app, that can help distinguish an access problem from a local Outlook setup or synchronization issue.

Troubleshooting

The mailbox address is not found or cannot be added. Check the spelling and domain, then confirm with IT that the mailbox exists and that your signed-in account has Full Access. Make sure you are signed in with the work account that was granted permission, not a personal Microsoft account or a different organizational account. If permission was just granted, wait and try again later. Ask the administrator to verify the access assignment and whether your organization allows that Outlook client to open shared mailboxes.

The mailbox was added but does not appear. Expand the folder pane and look below the correct account; a collapsed navigation pane can hide it. Close and reopen Outlook, then allow the folders to synchronize. In classic Outlook for Windows, confirm that the address was added under the intended account in More Settings > Advanced. If you have more than one work account, verify you added it under the account that received permission.

You can see the mailbox but cannot send from it. This usually means you have access to read the mailbox but do not have the necessary sending permission, or Outlook is using your own From address. Ask the mailbox administrator to grant the appropriate Send As or Send on Behalf permission. Reopen Outlook after the permission is updated, create a new message, and explicitly select the shared address in From. If a message is rejected, keep the exact error text and share it with IT.

Messages are missing, or the mailbox looks out of date. Check that you are looking in the shared mailbox’s folder rather than your own Inbox, and allow time for synchronization. Refresh or restart Outlook. If only one client has the problem, compare with Outlook on the web; if the same folders or messages are missing there too, contact the mailbox owner or IT. Retention rules, folder permissions, and organizational policies can affect what you can see.

You get repeated password prompts. A shared mailbox is generally opened through your own authorized account, not by signing in with the shared address. Cancel the prompt rather than guessing credentials, confirm which account Outlook is using, and contact IT if the prompt continues. The administrator can check your account sign-in and mailbox permissions.

Frequently Asked Questions

Do I need a password for a shared mailbox?
No, not usually. You sign in to Outlook with your own work or school account, and the mailbox is opened because that account has permission. Do not use another employee’s password. Your organization’s administrator manages the mailbox and access.

Can I add a shared mailbox to personal Outlook.com?
Shared mailboxes are generally an Exchange or Microsoft 365 work or school feature. A personal Outlook.com account normally cannot open an organization’s shared mailbox unless the organization has set up an account and access arrangement that supports it. Ask the organization’s IT team which account and Outlook app to use.

Why can I read the mailbox but not send messages from it?
Reading and managing messages requires Full Access, while sending from the shared address requires Send As or Send on Behalf permission. Ask the mailbox owner or administrator to confirm which permission you have. Then select the shared address in the From field when composing.

Will the mailbox appear automatically in Outlook?
It may. In some Microsoft 365 and Exchange setups, Outlook for Windows automatically maps a mailbox after Full Access is granted. Mapping can take time and is not available in every configuration or client. If it does not appear, use the steps for your Outlook version or ask IT whether manual addition is supported.

Can I add the same mailbox on more than one device?
Usually, yes, provided each device is signed in with the account that has permission and the Outlook app supports shared mailboxes. Add it separately on each device if it does not sync as an account-level folder. Availability and menus differ between Windows, Mac, web, and mobile.

What is the difference between Send As and Send on Behalf?
With Send As, the message appears to come directly from the shared mailbox. With Send on Behalf, recipients can see that your account sent it on behalf of the mailbox. Your organization decides which permission to grant, so ask which identity is appropriate for your role.

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