Subscribe to notifications for a poll:
Using a Doodle account you can always subscribe to notifications after participating in or commenting on the poll. You can do so directly underneath the poll table.
Unsubscribe from notifications for a poll:
Open the poll again and click on "unsubscribe to updates"
You can also unsubscribe from notifications using the unsubscribe link you will find in any of the e-mail notification you have received. Unsubscribing from there will unsubscribe you from all notifications of that poll.