You can send a notification email any time you want (to the followers of a post).
It can be used to ask for feedback on a proposal or any other item.
Click the notification icon and choose "email notification".
Users will receive an email similar to below.
You can easily see what notifications have been send to which users.
Note: Emails will not be send to the user that made the status change. Emails will also not be send to users that have not accepted their invite or verified their emailaddress.