This video will show you how to use the Inbox application on a day-to-day basis. The Inbox application will centralize all the notifications that are most important to you (comments, status on tasks and milestones, new files etc..).
In GroupCamp, Email notifications icon of the Admin Panel allows you to manage the way email notifications are sent.
This video from GroupCamp shows how to to use GroupCamp's Gmail Gadget to create tasks in a project and post messages in groups.
This video from GroupCamp shows how to create a task from your email or how to use the task email dropbox feature.