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The default subtab is My Incoming, which is like your inbox. All My Email is a combination of My Incoming and My Sent. There's also My Unread for unread messages, and My Today for just today's messages. Finally, All Incoming is a subtab that only admins see, allwoing them to read everyone's email.
Each email has a checkbox on its left that is used to Delete or Mark As Read messages in bulk. Many messages also have a Go To Lead button if the message is associated with a lead.