Check your version
This tutorial covers a topic in Drupal 7 which may or may not be the version you're using. We're keeping this tutorial online as a courtesy to users of Drupal 7, but we consider it archived.
Alternate resources
Rules guide (Drupal.org)
Sprout Video
This screencast shows how to set up Rules to allow comment writers to be notified when replies are posted to their comments. It covers:
- Adding a checkbox to the comment form, turning on or off reply notifications
- Sending e-mails to the comment author when new comments are posted
- Not sending e-mails when replying to own comments
- Some words about checking “entity has field” on the correct entity
Additional resources
Rules guide (Drupal.org)