How to Add a Shared Mailbox in Outlook Mobile

To add a shared mailbox in Outlook mobile, sign in to the Outlook app with your work or school account, open the account menu, choose Add Account and then Add Shared Mailbox. You must already have permission to access the mailbox; adding it in the app does not grant access. The steps below apply to Outlook for iOS and Android, though labels and icon positions can vary slightly between app versions.

What You’ll Need

Outlook for iOS or Android. Update the app from the App Store or Google Play if you cannot find the shared-mailbox option.
Your organization account. Sign in with the Microsoft 365 work or school account that has access to the shared mailbox. A shared mailbox is normally opened through your own account rather than by signing in with a separate shared-mailbox password.
Permission from your Microsoft 365 or Exchange administrator. Ask for Full Access or the relevant mailbox access before setup. If you need to send messages as the mailbox, ask for Send As or Send on Behalf permission as well; reading access does not necessarily include sending permission.
The mailbox address. Have its full email address ready, especially if your organization has several shared mailboxes with similar names.
An internet connection and a supported work account. Your organization may also require device security, multifactor authentication, or an approved sign-in method.

Step-by-Step

Open Outlook and check your signed-in account. Launch Outlook on your iPhone, iPad, or Android device. If prompted, sign in with the work or school account that was granted access. If you have both personal and work accounts in Outlook, check which account is active before adding the mailbox; permission is associated with the organizational account, not simply with the app installation.
Open the account menu. Tap your profile picture, initials, or account icon near the upper-left corner. Depending on the app layout, you may first see the mail navigation menu or a list of accounts. Look for the account-management option, usually shown as a plus sign or the words Add Account. If you see a gear icon instead, open Settings and look for Add Account there.
Choose the shared-mailbox option. Tap Add Account, then select Add Shared Mailbox. Do not choose the ordinary option for adding a personal or work account unless your administrator has specifically told you to add a separate licensed account. Outlook may ask you to select the work account that should be used to access the mailbox.
Enter the shared mailbox address. Type the complete email address, such as helpdesk@example.com, and continue. Check spelling and the domain carefully. If Outlook offers a list of matching mailboxes, select the one your organization authorized. Depending on your setup, the app may discover the mailbox automatically after you choose your account.
Complete any sign-in or security prompt. If asked, authenticate with your own work or school account and complete multifactor authentication or your organization’s device verification. Do not enter a shared mailbox password unless your IT administrator has explicitly confirmed that your organization uses a separate account for it; typical Microsoft 365 shared mailboxes are accessed through delegated permissions.
Wait for Outlook to add and sync the mailbox. The mailbox may take a short time to appear, particularly the first time it loads or when the network is slow. Return to the mail view and open the account or folder list. You should see the shared mailbox listed separately from your personal or primary work inbox. Tap its name, or tap its arrow to expand the folders, to view its Inbox and other available folders.
Open a folder and confirm you can read messages. Select Inbox under the shared mailbox, rather than the Inbox under your own account. Open a recent message to confirm that the mailbox is working. If it appears empty, check that you selected the correct mailbox and folder and allow time for synchronization before treating it as an access problem.
Test sending only if you have permission. Start a new message and look for the From field or sender address. Tap it to choose the shared mailbox as the sender; in some versions, the field is revealed through a small arrow or the message’s additional options. Send a brief test to an address you control only if your organization allows it. If the mailbox is not available as a sender, you may have reading access but lack Send As or Send on Behalf permission.

After setup, you can switch between your own mailbox and the shared one from the account or folder list. Keep track of which mailbox is selected before replying or composing, because a reply started from the wrong Inbox may be sent from your personal work address instead.

Common Mistakes

Trying to add the mailbox before access has been granted. Outlook cannot create permission when you type an address. Ask your Microsoft 365 or Exchange administrator to grant access to your own account, then try again. Permission changes may take time to reach the app.
Signing in with the shared address as if it were a normal account. A shared mailbox generally does not have its own sign-in credentials for everyday access. Use the work account that has been delegated access. Using a password someone supplied for the shared address can fail or create security and account-management problems.
Confusing Full Access with permission to send. Full Access lets you open and manage mailbox contents, but it does not automatically mean you can send as that address. Request Send As or Send on Behalf separately if needed, and allow time for the permission to take effect.
Adding the address through the wrong menu. Choosing the regular Add Account option may start a sign-in flow instead of attaching the mailbox. Go back and select the specific shared-mailbox option. If it is missing, update Outlook and check whether your organization supports the feature.
Replying from the wrong account. Seeing a shared message does not guarantee that the shared mailbox is selected as the sender. Check the From line before sending, especially when switching quickly between mailboxes.

Tips

Ask for the exact address and permission names. An administrator can confirm the mailbox address, which account has access, and whether you have Full Access, Send As, or Send on Behalf. This makes it easier to tell an app issue from a permissions issue.
Give access changes time to propagate. After an administrator adds you, wait a while, then close and reopen Outlook or refresh the mailbox list. The delay can vary by organization and service conditions; repeatedly removing and re-adding the mailbox is not usually the first fix.
Use clear mailbox names when choosing a sender. If several addresses appear in the From picker, verify the full address before sending. This is particularly helpful for teams that share customer support, billing, or departmental mailboxes.
Keep the app current and use your organization’s approved account. Outlook’s menus can move as the app changes. Updating it can restore missing options and improve compatibility with current sign-in requirements. If your employer manages mobile apps or devices, follow its setup instructions rather than bypassing a security prompt.
Remember that mobile and desktop layouts differ. Outlook for Windows and Mac have different account and mailbox controls. Instructions for adding a mailbox in desktop Outlook may not match the mobile app, so use the mobile account menu for this process.

Troubleshooting

The Add Shared Mailbox option is missing. Update Outlook, then check the profile or account menu and Settings for Add Account. Confirm that you are using the Outlook mobile app and a work or school account. If the option still does not appear, your organization may restrict shared mailbox access on mobile or use a configuration that requires IT support.
Outlook says the mailbox cannot be found. Re-enter the full address, including the correct domain, and check for typos. If the address is right, ask your administrator whether the mailbox exists, is a shared mailbox, and has been provisioned for your organization’s Exchange environment.
You see an access-denied message or an empty mailbox. Verify that your administrator granted permissions to the exact account signed in to Outlook. If you have more than one work account in the app, select the correct one. Ask the administrator to confirm access and allow time for the change to take effect. Also check that you opened the shared mailbox’s Inbox, not your own.
The mailbox was added but is not syncing. Check that your phone has a working network connection, then refresh the mail view or close and reopen Outlook. If only one folder is affected, open another shared folder and return to the Inbox. If the problem continues, contact IT before removing the mailbox, since you may need to repeat setup and reselect the correct account.
You can read messages but cannot send from the mailbox. Ask for Send As or Send on Behalf permission, as appropriate for your organization. Once granted, allow time for the change to apply, restart Outlook, and check the From picker again. Do not send from your own address if the message must come from the shared address.
Sign-in loops or security prompts keep returning. Complete the organization’s multifactor authentication steps, make sure Outlook is updated, and check whether your device must be registered or managed. If the prompt names a policy or says access is blocked, contact your help desk; changing passwords or repeatedly reinstalling the app may not resolve an organization policy restriction.

Frequently Asked Questions

Can I add a shared mailbox in Outlook mobile without an administrator?
If access has already been granted to your work account, you can usually add it yourself using the steps above. You cannot grant yourself mailbox permissions. If Outlook refuses access, ask your Microsoft 365 or Exchange administrator to check the permissions.

Do I need a separate password for the shared mailbox?
Usually not. Microsoft 365 shared mailboxes are typically accessed through your own organizational sign-in and delegated access. Do not try to sign in directly as the shared mailbox unless your IT administrator gives you a specific, supported reason to do so.

Can I send email from the shared mailbox in Outlook mobile?
Yes, if your organization has granted the necessary sending permission and the mobile app exposes the shared address in the From picker. Full Access alone may not be enough. Check the sender address before sending each message.

Will adding it on my phone add it to Outlook on my computer?
Not necessarily. Adding the mailbox in the mobile app configures Outlook on that device. Desktop Outlook may show it automatically in some Exchange configurations, or you may need to add it separately using your organization’s desktop instructions.

Why can I see the mailbox in Outlook on my computer but not on my phone?
Mobile availability can depend on the app version, signed-in account, permissions, and organization policies. Confirm that the same work account is being used on both devices, update Outlook mobile, and ask IT whether mobile access to shared mailboxes is allowed.

Can I remove the shared mailbox later?
Yes. Open Outlook’s account or Settings area, select the shared mailbox, and use the available remove or delete-account option. The wording can differ by app version. Removing it from the app does not delete the mailbox or revoke the permissions your administrator assigned.

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