Why there's no email delivered when I set the "Notify users that this content has changed"?

[kunikotakahashi]

There's a feature named "Notify users that this content has changed" in Assignments and Quizzes as the attachment.

But when I check this checkbox, there's no mail delivered.

I've already enable the notification in Account>>Notification. And about the notification feature of others, mails can be delivered successfully. So I'm considering that "Notify users that this content has changed" in Assignments and Quizzes is not supported in OSS version which I'm using now.

Does anybody know about this?

Thank you very much!