Mails not working

Hi,

A blog of mine is using WordPress version 2.8.4. It is a multi-user blog. I want that whenever someone posts some comment on some blog post then mail should go to author of the post. In settings, I have already checked the setting that mail should go whenever comment is posted.

Also I have enabled wp-email plugin on my blog site. As the server on which this blog site is deployed, uses smtp protocol to send mail so I have provided smtp server settings with username, password and port in following files:

php.ini
pluggable.php
class-mailer.php
email-options.php

But still mail is not working.

Any kind of help on this will be much appreciated.

Thanks,
Bhawana