Add Shared Mailbox on Mobile Device with Outlook App

Overview

If you have access to a shared mailbox in Outlook on your desktop, then it is possible to add that mailbox to your phone with the Outlook mobile app.

Instructions

If you do not already have it, download the Microsoft Outlook mobile app on your phone or tablet:

Google Play Store: https://play.google.com/store/apps/details?id=com.microsoft.office.outlook&hl=en_US
Apple App Store: https://apps.apple.com/us/app/microsoft-outlook/id951937596

Once downloaded, you will need to open the app and sign-in to your own Microsoft 365 account if not already added:

If setting up Outlook for the first time:

Tap Add Account.
Enter your email address and your Windows password.

If you already have another account added to your Outlook app:

Tap the profile icon in the top-left corner.
Tap the settings cog in the bottom-left corner.
Tap Accounts and then tap Add Account.
Tap Email Account and then sign-in with your email address and your Windows password.

After signing-in to your own Microsoft 365 account in the Outlook mobile app, you can now add any shared mailboxes which you can already access:

Tap the profile icon in the top-left corner:

Tap the settings cog in the bottom-left corner:

In the Settings menu, tap Accounts.

On the Accounts page, tap Add Account.

On the Add Account page, tap Shared Mailbox.

Enter the email address for the shared mailbox you want to add and then tap Add Shared Mailbox.

Once added, it will now appear in your Accounts list.

Note: if you do not have permissions to view the mailbox, then you will not be able to add it here.

To view the inbox for this shared mailbox, exit out of the Settings menu and then return to the inbox screen. From here, you can switch between your accounts by tapping the profile icon in the top-right corner and then selecting the mailbox you wish to view.