We are attempting to enable Notification Rules to keep our users informed.  However, last night we tested four and only one actually worked. We turned on Acknowledge sender by e-mail when a new request if received, Acknowledge requester by e-mail when a request is updated, Acknowledge requester by e-mail when the request is closed, and Notify requester when a request is assigned to a technician, and only the first of those generated an email.  Firstly, is there a difference between the terms Acknowledge and Notify that is important?  Also, any ideas why these notifications are not triggering?