Your Triage filter allows you to select what items show in your view. 

All: Every Triage item will appear

Unread: Any items you have not read will appear

Email: Only emails are shown

Mentions: Any item (Task, Email, Note) where a comment has been added that includes an @mention of you, or a team you are involved in

Notifications: All Triage items, excluding emails (Client Tasks, Work assignments, Notes and Tasks where you have been @mentioned)