How to Add a Shared Mailbox in Microsoft Outlook

To add a shared mailbox in Outlook, first ask your Microsoft 365 or Exchange administrator to grant your account access, then add the mailbox in Outlook or wait for it to appear automatically. In new Outlook for Windows, right-click your account name in the folder pane and choose Add shared folder or mailbox. The exact menu differs in classic Outlook and on Mac, so follow the instructions for your version below.

A shared mailbox lets a team read and manage messages sent to a common address, such as support@ or accounts@. It is not normally a separate account that you sign into with its own password: you open it from your own Outlook account after an administrator gives you permission.

What You’ll Need

Permission to the mailbox. Ask the mailbox owner or Microsoft 365 administrator to grant your work or school account access. Full Access lets you open and manage its contents; Send As or Send on Behalf is needed if you also need to send from the shared address. These permissions are separate.
The mailbox address. Get the full email address, not just the display name, and confirm that it is a shared mailbox in your organisation’s Microsoft 365 or Exchange environment.
A supported Outlook account. Be signed in to the work or school account that was granted permission. Personal Outlook.com accounts generally cannot open an organisation’s Exchange shared mailbox unless the organisation has specifically configured access.
A little time for permissions to take effect. New or changed access may not be available immediately. If the mailbox was just created or permission was just granted, allow some time and restart Outlook before assuming the setup failed.

Step-by-Step

Confirm your access before changing Outlook settings. Contact the mailbox owner or IT team and ask them to confirm that your exact work account has Full Access. If you need to send messages from the shared address, ask for Send As or Send on Behalf as well. Tell the administrator whether you need to read mail, send mail, or both. Adding an address in Outlook does not grant permissions by itself.
Check whether Outlook has already added the mailbox. Close and reopen Outlook, then inspect the folder pane on the left. Look below your own account for another mailbox name. Exchange may automatically map a shared mailbox to your profile after Full Access is assigned. Expand the mailbox arrow to see folders such as Inbox, Sent Items, and Drafts. If it is present, you can skip the manual add steps and open its folders.
Add it in new Outlook for Windows if it is not listed. Open Mail and expand the folder pane if it is collapsed. Right-click your account name, usually shown near the top of the folder list, and select Add shared folder or mailbox. Enter the shared mailbox email address, select the matching result if Outlook offers one, and choose Add. The mailbox should appear in the folder pane. Expand it to open its Inbox or another folder.
Add it in classic Outlook for Windows if needed. In classic Outlook, 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 Mailboxes. Enter the shared mailbox name or address, select OK, then select Apply and OK to close the windows. Finish any prompts, close Account Settings, and restart Outlook. Menu labels can vary slightly by Outlook build or organisation configuration. If the Add button is unavailable, use the automatic mapping route or contact IT rather than adding the shared address as a separate login.
Open the mailbox in Outlook for Mac. In many current Outlook for Mac versions, select Tools > Accounts, choose your work or school account, then open Delegation and Sharing. Under Shared With Me, choose the plus button, enter the mailbox address, select the matching mailbox, and add it. In some newer or different Mac builds, use File > Open > Shared Mailbox, enter the address, and confirm. If neither path appears, update Outlook and check with your administrator; Mac menus can differ by release and account type. When it has been added, look for it in the folder list and expand it.
Use Outlook on the web if you cannot install or configure the desktop app. Sign in to your organisation’s Microsoft 365 Outlook page. In the folder pane, right-click Folders or your account name and choose Add shared folder or mailbox, then enter the address and add it. Depending on your organisation’s Outlook web layout, the command may be under the three-dot menu instead. This opens the mailbox in the folder list without changing your desktop Outlook profile.
Test that you can read mail. Open the shared mailbox Inbox and select a recent message. Check that you can view its contents and, if required, open other folders. If the mailbox name appears but the folders do not load, wait briefly, refresh or restart Outlook, and check with IT that Full Access was granted to the account you are using.
Test sending only if you have sending permission. Start a new message and display the From field if it is hidden. In classic Outlook for Windows, use Options > From; in other Outlook versions, look for the From control in the compose window. Choose the shared address from the list or select Other Email Address and enter it. Send a brief test to yourself or a colleague, following your organisation’s policies. If Outlook rejects the address, the mailbox may be open correctly but your account may not have Send As or Send on Behalf permission.

Common Mistakes

Trying to add the mailbox before access is granted. Outlook cannot make an unpermitted mailbox available. Ask the administrator to check the permission assignment and the account address, then retry after the change has had time to apply.
Entering the shared address as a new sign-in. A shared mailbox usually does not have a password for staff to use. Do not request or use shared credentials; sign in with your own approved work account and add the mailbox to it.
Assuming access to read means permission to send. Full Access, Send As, and Send on Behalf are distinct permissions. Ask for the specific sending permission that matches your team’s needs.
Adding it repeatedly. If the mailbox is already auto-mapped, adding it manually can create duplicate entries or confusing folder lists. Search the folder pane carefully and restart Outlook before adding it again.
Using the wrong Outlook profile or account. A mailbox granted to one work account will not necessarily open under another account in the same app. Confirm the signed-in address before troubleshooting further.

Tips

Give the mailbox a useful label. If Outlook displays a long or unclear mailbox name, ask the owner or administrator whether its display name can be made recognisable. This helps distinguish shared mail from your own Inbox.
Use the shared Inbox as the team source of truth. Agree on a simple process for assigning, flagging, or categorising messages so two people do not unknowingly work on the same request. Avoid moving or deleting messages if your team has a retention or records process.
Understand where sent mail is stored. Depending on how Exchange and the mailbox are configured, a message sent using the shared address may be saved in your personal Sent Items or the shared mailbox Sent Items. If teammates need to see the replies, ask IT to check the organisation’s sent-item settings.
Close only the folder pane, not the mailbox. If you do not see the shared mailbox, expand the account or folder list, or widen the pane. It may simply be collapsed rather than removed.
Keep your own account secure. Since access is granted through your account, use your organisation’s sign-in and multi-factor authentication requirements. Report access you no longer need so the administrator can remove it.

Troubleshooting

The mailbox does not appear. Confirm that IT granted Full Access to the exact account currently signed in. Wait for permission changes to propagate, then restart Outlook. In classic Outlook, also check whether it is already listed under the account’s folder tree. If it remains missing, ask IT to verify that the address is a shared mailbox and that your account is allowed to access it. Do not keep adding alternate spellings or create a new account for it.

Outlook says the mailbox cannot be found or opened. Check for a typo and try the full email address rather than the display name. Confirm you are connected to the internet and signed in to the organisation’s Exchange account. If the mailbox was recently created, it may not be ready yet. An administrator can check the mailbox status, access rights, and whether your organisation’s account or licensing setup supports the requested access.

The mailbox opens, but sending fails. This usually points to missing or incomplete sending permission rather than a problem opening the mailbox. Ask the owner or IT for Send As or Send on Behalf, as appropriate, and wait for the change to take effect. When composing, make sure the From field contains the shared address. If the message sends but appears under your own name, check that the correct From address was selected and ask IT to review permissions.

The mailbox appears twice or folders look out of date. Check whether Outlook auto-mapped the mailbox as well as a manually added entry. Ask IT which entry to keep, remove only the extra manual listing if your Outlook version offers that option, and restart the app. If folder contents still look stale, refresh the view or sign out and back in only if your organisation’s support team recommends it. Avoid deleting messages as a way to refresh the mailbox.

The instructions do not match your screen. Outlook has new and classic Windows interfaces, and Mac menus vary by version. Check whether the app is labelled new Outlook and use its shared-folder command, or switch to the classic Outlook instructions where available. If your organisation manages Outlook centrally, its IT team may disable a menu or require access to be added for you. Provide them with your Outlook version, operating system, account address, and the exact error text.

Frequently Asked Questions

Does adding a shared mailbox give me permission to it?
No. An administrator or mailbox owner must first grant your account access. The Outlook add command only displays a mailbox that your account is permitted to open.

Why did the shared mailbox appear automatically?
Exchange can automatically map a mailbox to Outlook when Full Access is assigned. Restart Outlook and check the folder pane before adding it manually. Automatic appearance does not necessarily mean you can send from its address.

Can I add a shared mailbox to Outlook on my phone?
Often, yes, if your organisation allows it and your account has permission. In the Outlook mobile app, tap your profile icon, use the add-account control, and choose the option to add a shared mailbox if it is shown. Select the work account with access and enter the mailbox address. App versions and organisation policies can change the available options; ask IT if the choice is missing.

Can I use a shared mailbox without a password?
Usually, yes. Sign in to Outlook with your own work account and open the shared mailbox through that account. Do not try to sign in as the mailbox or share credentials unless your organisation’s administrator explicitly directs you through an approved process.

What is the difference between Send As and Send on Behalf?
Send As makes the message appear to come from the shared mailbox. Send on Behalf indicates that you sent it on the mailbox’s behalf. Your organisation decides which permission to grant; ask for the one that fits your team’s communication practice.

How do I remove a shared mailbox from Outlook?
For a manually added mailbox, remove its listing using the relevant account or folder controls in your Outlook version. If it was automatically mapped, ask IT to remove your Full Access permission; deleting a local listing may not stop it from returning. Removing a mailbox from your view does not delete the mailbox or its messages.

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

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