Fields CC and Reviewer doesn't send alerts to inbox

I remember that fields CC and Reviewer sending alerts to inbox for users who will add to this fields. But now it doesn’t working.
I know that I can do it if I click to button FOLLOW on page task. But it is not usefull. Because, if I want to tune it for all project, I must to login to account all users and click this button. I’ve 30 users in my company. And every month we start new series. It is about 200 shots with 10 tasks for every shot. And I must to click this button for every 2000 tasks for everyone user. :frowning:
Could you suggest some other way?