Shared mailboxes allow a group of users to view, send email, and share a calendar from a common mailbox. If you want to access shared mailbox, you can use following steps: –

1. Sign in to your account in Outlook Web and click on outlook onto the top.
2. Click on the account name button on the top-right corner and select “Open another mailbox…” from the drop-down list.
3. Search for the shared mailbox that you wish to open. Select the appropriate shared mailbox.
4. Now, click on “Open” button.
5. Now, you can see shared mailbox on your window screen.
6. Right click on this shared mailbox. Some option appears in the list. You can use any of these options, as per your requirement.