I just checked SO16, it's configured to send the notifications to the Home Address of Users.
the good news is, it appears that I assigned my user ID to the "Department" but with limited validity which has already expired, this is why I wasn't getting the notifications, I extended the validity and I'm now getting the notification of completion, and just to confirm the first point, the notification of completion goes to the people assigned to the Organizational Element, not to the mail address infotype of the Organizational element itself.
Thank you for the help.