Unable to send email using PHP mail().

[eluser]emuexplosion[/eluser]

Code:

Unable to send email using PHP mail().  Your server might not be configured to send mail using this method.

What I don't understand from this print_debugger() error is that my server uses mail() just fine. If I test a simple mail using..

Code:

<?php
$mail = mail('[email protected]', 'subject', 'msg');
?>

.. it sends just fine. I'm using the same code to send an e-mail copied from another CI website I have.. the only thing that differs is the server. What about the server could cause this? Both are cPanel, one is a VPS (e-mail works), one is a dedicated server (e-mail doesn't work).. but both are setup within cPanel the same.

I'm stuck.