Can't modify php.ini - other ways of getting email to work?

[E2E]

Hi there, I'm back to working on this problem after some time away from it and was wondering if anybody could help me: After working with my host company for a while I've -finally- been able to confirm that things -are- set up correctly on their end for php/smtp mail to work -- in fact I was able to get the following code, which is their recommended way of enabling php/smtp mail on their server, to work:

<?
require("c:\php\includes\class.phpmailer.php");

$mail = new PHPMailer();

$mail->IsSMTP();
$mail->Host     = "sendmail.brinkster.com";
$mail->SMTPAuth = true; // This line is important for smtp authentication
$mail->Username = "Validbrinkster@hostedemail.com";
$mail->Password = "EmailPassword";

$mail->From     ="Validbrinkster@hostedemail.com";
$mail->FromName ="Validbrinkster@hostedemail.com";
$mail->AddAddress("Valid@emailaddress.com"); 
$mail->IsHTML(true);
$mail->Subject  =  "Email Subject";
$mail->Body     =  "Email Body";

if(!$mail->Send())
{
   echo "Message was not sent <p>";
   echo "Mailer Error: " . $mail->ErrorInfo;
   exit;
}
echo "Message has been sent";
?>

My problem is that I've not been able to update my mail.php file to make -it- work correctly for my vBulletin forum (despite the fact that I've followed the steps in Zachery's linked "How to enable SMTP" thread) and I just don't have enough php/vBulletin experience to understand what the problem could be. Since I -know- the code above works with my host, would it make sense to somehow incorporate that into my mail.php file? If that would make sense, could someone point me in the right direction as to what specific pieces I would -have- to include and in what way? Are there other solutions anyone might suggest?

As always, thanks in advance to anyone who might help me out with this =)