Email notification for Status Changes
How to set Email notification for Status Changes?
To set email notification for status changes, go to Notifications>Community Name>Receive e-mail notifications on Idea status change

Realtime subscribers will receive an email when the status changes :
"In Review" to "X" "X" to "Completed"
The author of Idea will get email when status changes:
"Inbound/Pending" to "Active" "Inbound/Pending" to "Closed"