Add a shared mailbox to your mobile device
They can also be mailboxes belonging to someone else to which you have delegated access. This might be your manager’s email account, for example.
Shared mailboxes are only supported in the Outlook app on phones and iPads, so if you haven’t already, you’ll need to be using that app for your work email. See here for Apple devices and here for Android phones.
After you’ve added your primary account to the Outlook app, tap the three-line menu in the top-left corner, then tap the Add Account button.
Tap Add a shared mailbox.
If you have multiple accounts in the Outlook app, under Select an account to log in with tap your primary work account; the one which has permission to access the shared mailbox.
Enter the email address of the shared mailbox you wish to add, then tap Continue.
The shared mailbox will display in your account list in the Outlook app.
To remove a shared mailbox, go to Settings > Accounts. Then tap on the shared mailbox and select Delete Account.