These options exist. Go to your profile > notifications.

@fplanque wrote:

These options exist. Go to your profile > notifications.

I see...
But it's seems basing on the email system,only using the email notification maybe have following disadvantages
1. Email is not frequently used, perhaps not only in our country. Many people don't get a email account yet, they use email only when needing some verification.I know the email must be completed during the registration, but few people would see it every day and time. This is the computer using habit in our country, may be some other counter also got similar problems.

2. Many people want to see the notification when they loggin. Notifications be showed on the frondpage when the user login in should be more simple and intuitive. Just like the private message notification.Email notification is really realtime, but not easy to search and find. Email just like a big bucket having messages at sixes and sevens. After one day, whan I login in the website, may be I had forgotten the notification, or may be I should reopen the email to find which topic I should reply!

In summary, it is necessary to have an independent notification system! It will be much useful to find and reply an post or comment!