Send notification E-Mail to x when x’s content is commented
Use Rules module. Create the following Rule:


Event: after saving a new comment. You will probably want to restrict this by content type as well.
Add action: send mail. Arguments:


To: switch to data selection and choose comment:node:author:mail
Subject: whatever you want, for example "A comment has been posted to your blog post"
Add the message
Condition: NOT comment:node:author:uid and comment:author:uid so that the user does not receive emails for his own comments.



Here's how to insert the name of the node author:

Formatted username:

Dear [comment:node:author:name], [...]


Specific field (e.g. if you have first and last name fields and you want to use only first name):

Dear [comment:node:author:field-first-name], [...]