Shared mailboxes

You can edit a lot of the properties of a shared mailbox by using the shared mailbox panel when you click on one of the shared mailboxes on this page:

The Shared mailboxes page

Using this panel, you can edit the name, email, email aliases, forwarding, auto-replies, litigation hold status, membership, and other settings, such as whether sent items get copied to the mailbox, whether the mailbox is in the global address list, and so on. You can also delete the mailbox, go directly to Exchange administration to work with the mailbox, or read about how to use Shared mailboxes in Outlook:

The shared mailbox panel

Again, there's a lot less functionality for actually creating mailboxes. You can set the name and the email address, and that's all. For all other properties, you'll need to wait for it to be created, and then edit it.