Add a Shared Mailbox in Outlook for Mac: Setup Guide

To add a shared mailbox in Outlook for Mac, open File > Open > Shared Mailbox, enter the mailbox email address, and choose Add. You must already have permission to access it through your work or school Microsoft 365 or Exchange account. If that menu is missing, use the alternate steps below for your Outlook version.

What You’ll Need

An Outlook account connected to your organization. A shared mailbox is normally provided by a workplace, school, or other organization using Microsoft Exchange or Microsoft 365. A personal Outlook.com account generally cannot access an organization’s shared mailbox.
Permission to use the mailbox. Ask the mailbox owner or Microsoft 365 administrator to grant your account access. Full Access lets you open and manage mailbox contents. Sending from the shared address may require a separate Send As or Send on Behalf permission.
The mailbox address. Get the full email address, such as support@example.com, from the owner or administrator. A display name alone may not identify the right mailbox.
A current, signed-in Outlook for Mac app. Update Outlook if possible and confirm that the work or school account with access is already added. Your menu labels can differ slightly between New Outlook and Legacy Outlook.

Step-by-Step

Confirm that you have access. Before changing Outlook settings, ask the mailbox owner or administrator to verify that your account has Full Access. If you need to send mail as the shared address, ask whether Send As or Send on Behalf permission has also been granted. These permissions are distinct: being able to open messages does not automatically mean you can send as the mailbox. If access was just granted, allow time for the change to reach Microsoft 365.
Open Outlook and select the account that has permission. Start Outlook for Mac and check that you are signed in with your organization account, not a personal account or another work account. If you have several accounts, the shared mailbox needs to be added under the account to which the administrator assigned access. Select Outlook > Settings > Accounts to review the accounts in the app. Do not remove or re-add an account just because the shared mailbox is not visible yet.
Try the direct shared-mailbox command. In the macOS menu bar, choose File > Open > Shared Mailbox. Enter the shared mailbox’s full email address when prompted, then choose Add or the confirmation button shown. If Outlook resolves the address to a name, check that the name and address identify the mailbox you were given. The mailbox should appear in the folder pane after Outlook finishes adding it. Depending on your Outlook build, the command may use slightly different wording.
If you use New Outlook and the command is unavailable, add it from the folder pane. In the left folder pane, look for Shared with me. Control-click or right-click that heading and choose Add shared folder or mailbox if the option appears. Enter the mailbox address and follow the prompts. If you do not see the Shared with me heading, expand the folder pane or check that you are using the account that has permission. This option is not displayed in every Outlook version.
Use account delegation settings if you have Legacy Outlook. In some Legacy Outlook for Mac builds, open Tools > Accounts, select the Exchange or Microsoft 365 account with access, and open Delegation and Sharing. Look for the section or tab called Shared With Me, select the add button, and enter the mailbox address. Older builds may instead show Tools > Accounts > Advanced > Delegates and an option to open additional mailboxes. If neither path is present, update Outlook or ask your administrator which method is supported for your organization.
Wait for the mailbox to load. After adding it, give Outlook time to retrieve the folder list and messages. The first sync may take longer if the mailbox has many folders or a large amount of mail. Expand the mailbox name in the folder pane to see folders such as Inbox, Sent Items, and Drafts. If the folder pane is collapsed, use its arrow or expand control rather than adding the mailbox again.
Check that you can open and read messages. Select the shared Inbox and open a recent message. Confirm that folders and message contents load, and that you are looking at the shared mailbox rather than your personal Inbox. If you cannot see the Inbox, expand the mailbox entry and check any folder list or sync indicators. Avoid moving or deleting a test message unless you intend to change the shared mailbox for everyone who uses it.
Test sending only if you have been authorized. Create a new message and select the shared address in the From field. If the From field is hidden, open a new message and use the message options to show it; the exact control varies by Outlook build. Send a brief, appropriate test to yourself or a colleague only if your organization permits it. If Outlook reports that you do not have permission to send, do not keep retrying: ask the administrator to confirm Send As or Send on Behalf access.

Common Mistakes

Trying to add the mailbox as an ordinary account. A shared mailbox is usually opened through an authorized account; it is not normally set up by signing in with a separate mailbox password. Do not ask for or use a shared password unless your organization’s administrator explicitly instructs you to use a supported sign-in method. Adding it as an independent account can cause sign-in errors and security problems.

Assuming access includes permission to send. Full Access, Send As, and Send on Behalf are different permissions. Full Access allows you to work with mailbox contents, but it does not necessarily allow you to send using the shared address. Ask for the exact permission required for your task.

Choosing the wrong account or mailbox address. If Outlook has multiple work accounts, permissions on one account do not necessarily apply to another. Confirm both the signed-in account and the full shared address before repeating the setup.

Adding it repeatedly when it does not appear instantly. A delay can be caused by syncing or a recently changed permission. Adding the same mailbox several times can create confusion in the folder list. Wait, restart Outlook once, and check for the existing mailbox before trying again.

Tips

Use the shared address for replies when appropriate. When replying to a message from the shared Inbox, check the From field before sending. Outlook may use your personal address unless the shared mailbox is selected and you have the required sending permission.
Agree on folder and message practices with the team. Actions such as moving, categorizing, or deleting a message can affect other people using the same mailbox. Follow your organization’s conventions for assigning messages, keeping the Inbox clear, and using folders.
Allow for permission and sync delays. A newly assigned permission may not work immediately. Give the change some time, then close and reopen Outlook. If the mailbox still cannot be opened, ask the administrator to verify the permission on the correct account.
Keep Outlook updated. New Outlook and Legacy Outlook can have different menu layouts. Use Help > Check for Updates if that option is available, or update Outlook through the method your organization uses. If your organization requires a particular version, follow its update guidance.
Use Outlook on the web as a temporary check. If permitted by your organization, sign in to Microsoft 365 on the web with the account that has access and check whether the shared mailbox opens there. This can help distinguish a permission issue from a Mac app display or sync issue; it does not replace setting up the mailbox in Outlook for Mac.

Troubleshooting

The Shared Mailbox option is missing. Check whether you are using New Outlook or Legacy Outlook and try the matching folder-pane or account-settings route above. Confirm Outlook is open and that an organization account is configured. If you recently switched Outlook modes, close and reopen the app and inspect the File and Tools menus again. Menu availability varies by release and account type, so update Outlook if your organization allows it. If no route appears, ask your administrator or IT support which Outlook for Mac version and setup method your organization supports.

Outlook says the mailbox cannot be found or opened. Recheck the full email address for spelling errors, then verify that the account selected in Outlook is the account to which Full Access was granted. Ask the administrator to confirm that the mailbox exists, that your permission has been applied to your account, and that there are no restrictions on your organization’s setup. If permission was recently added, wait and try again later. Do not try random passwords or change the mailbox’s sign-in settings.

The mailbox appears but folders or messages are missing. Expand the mailbox in the folder pane, check that Outlook is online, and allow the initial sync to finish. Restart Outlook if the list remains incomplete. If only particular folders are missing, ask the mailbox owner whether those folders exist and whether your access includes them. Large mailboxes may take longer to display fully, and the app can show cached content while it synchronizes.

You can read messages but cannot send from the shared address. This usually means that Full Access is present but a sending permission is not, or that the shared address is not selected in the From field. Confirm which sender identity you are expected to use, then ask the administrator for Send As or Send on Behalf permission as appropriate. After it is granted, restart Outlook and try again. A successful reply from your personal address does not prove that sending as the shared mailbox is enabled.

The mailbox disappears or still will not sync. Confirm that you have not removed it and that your organization account remains signed in. Check your internet connection, restart Outlook, and see whether the mailbox is accessible in Outlook on the web if that is allowed. If it works on the web but not in the Mac app, give IT support your Outlook version, macOS version, account type, and the exact error message. Avoid deleting Outlook profiles or clearing app data unless support recommends it, as those steps can affect other account settings.

Frequently Asked Questions

Can I add a shared mailbox in Outlook for Mac without administrator help?

You can add it yourself if an owner or administrator has already granted your account the needed access. If Outlook cannot open it, the likely next step is to have the permission checked; the add-mailbox command cannot grant access by itself.

Do I need a separate password for the shared mailbox?

Usually not. You normally open a shared mailbox through your own authorized Microsoft 365 or Exchange account. Follow your organization’s instructions rather than attempting to sign in as the mailbox or requesting its password.

Why can I open the mailbox but not send from it?

Opening messages and sending as the mailbox require different permissions. Ask your administrator to check whether you need Send As or Send on Behalf access, and make sure the shared address is selected in the message’s From field.

How do I remove a shared mailbox from Outlook for Mac?

Use the same area where it was added and remove or stop displaying the mailbox, if that control is available in your Outlook version. In Legacy Outlook, check the account’s delegation or shared-mailbox settings. Removing it from your app does not delete the mailbox or revoke anyone’s access; ask IT if you cannot find the removal option.

Will the mailbox appear on my other devices?

Not always. Adding a mailbox to Outlook for Mac does not guarantee it will be added to Outlook on your phone, another computer, or Outlook on the web. Follow the setup steps for each app or device, and confirm you are using the account that has permission.

Can several people use the same shared mailbox?

Yes. Shared mailboxes are intended for multiple authorized users, subject to your organization’s configuration and licensing rules. Coordinate message handling with the team so people do not duplicate replies or unintentionally move or delete items others need.

Try it: the Date Difference Calculator: days, months, years and weekdays between two dates, with the DATEDIF formulas.

More in How-to basics

Sources: Function behaviour and menu paths: Microsoft Support documentation for Excel. Method & sources

Spotted an error in this guide? Let us know.