The Inbox is a quick way to view and respond to advocate only messages from the campaigns that you follow.
Navigating the Inbox Page
Click on the Inbox icon from the menu at the bottom
From the inbox page you can view messages from specific campaigns by clicking on the dropdown that says All My Campaigns
To view only unread messages click the Show Read switch so that it is turned off. You can also mark all messages as read by clicking on the Mark All Read button