Shared Mailboxes do not show in Outlook on the web.
a.sign into your account in outlook web app.
b. right-click your primary mailbox in the left navigation pane, and then choose to add a shared folder.
c. in the add shared folder dialog box, type the name or email address of the shared mailbox, and then click add.
2.
a.sign into your account in outlook web app.
b. on the outlook web app nav bar, click on your name. a list appears.
c. click open another mailbox.