Sending Email as HTML fails

[eluser]skunkbad[/eluser]
I can send email. As soon as I set the mailtype to html, it fails. Doesn't matter if it is in a config file, or set in the controller, fails either way. This is on a shared hosting account (linux) on IX webhosting.

Message: mail(): Bad parameters to mail() function, mail not sent.
Filename: libraries/Email.php
Line Number: 1519

I use this same code on two other hosts with no problems:

Code:

$this->load->library('email');
$this->email->from( set_value('email') , set_value('realname') );
$this->email->to( '[email protected]' );
$this->email->subject('Website Contact Message ' . date("M j, Y"));
$built_message['realname'] = set_value('realname');
$built_message['email'] = set_value('email');
$built_message['mesg'] = nl2br(set_value('mesg'));
$this->email->message($this->load->view('contact_email', $built_message, TRUE));
$this->email->send();

If the mailtype is not set as html, it sends the email, and the html characters are visible, and look otherwise perfect. Driving me crazy.