How to Add a Shared Mailbox Folder in Outlook 365

To add a shared mailbox folder in Outlook, first get permission to the mailbox or folder, then add the mailbox in Outlook and expand its folder list—or open the specific folder using classic Outlook’s Other User’s Folder command. You’ll need the shared mailbox’s email address and access granted by its owner or Microsoft 365 administrator. The exact steps depend on which Outlook app you use.

What You’ll Need

The shared mailbox or folder address. Usually this is the shared mailbox’s email address, such as support@example.com. For a folder shared from an individual’s mailbox, get the owner’s email address and the folder name.
Permission to access it. Full Access lets you open and manage the mailbox’s contents. A folder-specific permission, such as Reviewer, may let you read that folder without giving access to the entire mailbox. Send As permission is only needed if you also need to send messages as the shared mailbox.
A supported Outlook account. Sign in with the Microsoft 365 or Exchange account to which access was granted. If your organization manages permissions, an administrator may need to add you first.

Step-by-Step

Confirm what you have been given access to. Ask whether the request is for the whole shared mailbox or just one folder, and confirm the exact address and folder name. A shared mailbox and a folder shared from someone’s personal mailbox are not quite the same: adding a mailbox usually displays its folder tree, while opening one shared folder may require a separate command in classic Outlook. If the mailbox was just created or your access was just granted, allow time for the change to take effect before troubleshooting.
Choose the Outlook version you are using. In Outlook for Windows, the newer app is called new Outlook; the traditional desktop app is classic Outlook. The menus and ways of displaying a shared mailbox differ, so check the app’s name or appearance before following a path. Outlook on the web can also open shared mailboxes. On a Mac, use Outlook’s account and delegation settings when available, or use Outlook on the web if the sharing controls are not shown.
In new Outlook for Windows, add the shared mailbox. In the folder pane, right-click your account name or the Folders area and select Add shared folder or mailbox. Enter the shared mailbox’s email address, select the matching result, and choose Add. Depending on the version and layout, the shared mailbox may appear under a shared or shared-with-me section. Expand its name using the arrow beside it, then expand the relevant folder, such as Inbox, to display its subfolders.
In classic Outlook for Windows, add the whole mailbox if that is what you need. Select File > Account Settings > Account Settings. On the Email tab, select your Microsoft 365 or Exchange account and choose Change. Select More Settings, open the Advanced tab, and choose Add under the option for additional mailboxes. Enter the shared mailbox address, confirm the matching name, then select OK on each open dialog. Close and reopen Outlook if the mailbox does not appear immediately. Once it appears in the folder pane, expand it and open the folder you need.
In classic Outlook, open one folder shared with you. If you have permission to one folder but do not need the whole mailbox, select File > Open & Export > Other User’s Folder. Enter or select the owner’s name, choose the correct folder type from the list, and select OK. This opens the selected folder; it does not necessarily add the owner’s entire mailbox as a permanent mailbox tree. If the folder is not listed or Outlook reports that it cannot display it, ask the owner to confirm that they shared that exact folder and granted your account permission.
In Outlook on the web, add and expand the mailbox. Sign in to Outlook on the web with the account that has permission. In the folder pane, right-click Folders and choose Add shared folder or mailbox. Enter the shared mailbox address, select the correct result, and add it. Find the mailbox in the folder pane and expand it to show its folders. If you only have access to a particular folder, the available folders depend on the permissions granted; you may not see the rest of the mailbox.
On a Mac, add the shared mailbox through account settings if available. In Outlook for Mac, open Outlook > Settings > Accounts, select your Exchange account, and look for Delegation and Sharing or Shared With Me. Use the add control to enter the mailbox address, then close settings and check the folder pane. The exact controls can vary by Outlook version and account type. If you do not see those settings, try Outlook on the web or ask your administrator which Outlook app your organization supports.
Check that the intended folder opens. Expand the mailbox and select the folder by its name. Confirm that you can see the expected messages or other items. If you have read-only access, that can be correct: folder access does not automatically include permission to move, delete, or send items. To send from the shared address, you may need separate Send As or Send on Behalf permission and may need to select that address in a new message.

Common Mistakes

Assuming that an email address is enough. Knowing the mailbox address does not grant access. The mailbox owner or administrator must assign the appropriate permission, and you must open it while signed in to the account that received that permission.

Adding the wrong thing. Adding a shared mailbox is different from opening a single folder shared by a person. If you only need one folder, adding the entire mailbox may be unnecessary; if you need several folders, a folder-only route may not give you the convenient mailbox tree you expect.

Using the wrong Outlook instructions. New Outlook, classic Outlook, Outlook on the web, and Outlook for Mac do not have identical menus. For example, the classic Outlook Other User’s Folder command is not the same as adding a mailbox through account settings. Follow the steps for your app rather than looking for a menu that belongs to another version.

Expecting Send As access to come automatically. Being able to read a shared Inbox does not necessarily mean you can send from its address. Sending permissions are separate. Likewise, permission to read a folder does not necessarily allow you to edit it.

Changing permissions without confirming the owner. Do not try to change sharing settings on a mailbox you do not manage. Ask its owner or administrator to grant the correct access, especially if the folder contains confidential or restricted information.

Tips

Ask for the least access needed. If you only need to review messages, read access may be sufficient; if you need to organize or respond to them, explain which actions you need so the administrator can assign suitable permissions. Request access to the correct folder by its full path when there are several folders with similar names.

Use a recognizable mailbox name when checking the folder pane. Organizations sometimes have several shared addresses with similar names, such as support, sales, and regional support. Verify the email address before adding it, and check the mailbox name after it appears. This helps avoid reading or filing messages in the wrong place.

If you work in the mailbox regularly, leave it expanded or mark the relevant folder as a favorite where your Outlook version supports that option. This makes it easier to find without changing its permissions. Be cautious with actions such as moving or deleting messages: those changes affect the shared mailbox and may be visible to other people using it.

For teams, agree on how messages should be handled before several people work in the same folder. For example, decide whether staff should move completed messages to a subfolder or use categories. A shared mailbox is a common workspace, so consistent handling reduces duplicate replies and misplaced messages.

Troubleshooting

The mailbox or folder is not found. Check for spelling errors and verify that you are entering the mailbox address rather than a display name that matches several people. Confirm with the owner or administrator that permission was assigned to the account you are currently using. If access was granted recently, sign out and back in or restart Outlook, then try again.

The mailbox was added, but its folders are missing. Expand the mailbox using the arrow in the folder pane. If the arrow is absent or the folder tree is incomplete, close and reopen Outlook. In classic Outlook, check that the mailbox was added to the correct Exchange account under File > Account Settings > Account Settings > Change > More Settings > Advanced. If only a specific folder was shared, you may not have permission to see the mailbox’s other folders.

You see an access-denied message. Ask the owner or administrator to verify that your account has permission at the mailbox or folder level. For a folder-specific share, the owner should check the folder’s sharing or permissions settings and make sure they shared the intended folder with the correct account. Removing and re-adding it in Outlook will not fix missing permissions.

You can read messages but cannot move or delete them. Your permission may be read-only. Ask whether you need a higher level of folder access, and confirm that your organization permits those changes. Do not assume that Send As access or permission to view the mailbox also grants permission to edit every folder.

You can open the mailbox but cannot send from its address. Request Send As or Send on Behalf permission from the administrator if sending is part of your role. After it is granted, allow time for the change to update, then start a new message and select the shared address in the From field. If the field is not visible, enable it from the message window’s options; the exact control varies by Outlook version.

Outlook keeps prompting for credentials or shows stale content. Make sure you are signed in with your work or school account, not a personal Microsoft account. Update or restart Outlook and test the mailbox in Outlook on the web. If web access works but the desktop app does not, report the app version and error message to your IT team; organization policies or cached account details may be involved.

Frequently Asked Questions

Do I need Full Access to add a shared mailbox?
To open the whole mailbox, you generally need Full Access or the appropriate mailbox access granted by your administrator. If you only need one shared folder, folder-level permission may be enough, depending on your Outlook app and how the folder was shared.

Can I add just one shared mailbox folder?
Yes, in classic Outlook for Windows you can use File > Open & Export > Other User’s Folder to open a specific folder you have permission to access. Other Outlook versions may show a shared mailbox or shared folder differently, so use the app-specific steps above.

Why does the shared mailbox not appear automatically?
Automatic mailbox display depends on your organization’s Exchange setup and the type of permission assigned. If it does not appear, try adding it manually in your Outlook version or ask the administrator whether the permission has been applied to your account.

Will adding the mailbox add it for everyone?
No. Adding it in Outlook changes the view for your account, not for the rest of the team. Each person must have access granted and add or open the mailbox in their own Outlook profile if it does not appear automatically.

Can I add a shared mailbox to Outlook on my phone?
Outlook mobile supports shared mailboxes for many Microsoft 365 work or school accounts. In the app, tap the account or profile control, choose the option to add a shared mailbox, and follow the prompts. If the option is missing or the mailbox will not open, check with your administrator; mobile availability can depend on account setup and app version.

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