[CentOS] CentOS / BQ / PHP 4.3.9 with the mail() function

Hey everyone!

Got a little problem...with CentOS / BQ / PHP 4.3.9 with the mail() 
function

I'm able to send mail using postfix directly from the command line, 
however when I try using the mail function of php no mail is being sent. 
This simple script works on all my older Cobalt Boxs.

<? if($action=="send") {
$to      = 'me at domain.dot';
$subject = 'the subject';
$message = 'hello';
$headers = 'From: me at domain.dot' . "\r\n" .
  'Reply-To: me at domain.dot' . "\r\n" .
  'X-Mailer: PHP/' . phpversion();

mail($to, $subject, $message, $headers);
?>

the queue looks like this....
Jun 14 11:47:45 bq0 sendmail[19390]: j5EFljEU019390: from=<>, size=1146, 
class=0, nrcpts=0, proto=ESMTP, daemon=MTA, relay=localhost [127.0.0.1]
Jun 14 11:47:45 bq0 sendmail[19389]: j5EFljk1019389: j5EFljk2019389: 
return to sender: User unknown
Jun 14 11:47:45 bq0 sendmail[19390]: j5EFljEW019390: from=<>, size=3858, 
class=0, nrcpts=1, 
msgid=<200506141547.j5EFljk2019389 at bq.ontarioservers.com>, proto=ESMTP, 
daemon=MTA, relay=localhost [127.0.0.1]
Jun 14 11:47:45 bq0 sendmail[19389]: j5EFljk2019389: to=postmaster, 
delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=32170, 
relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (j5EFljEW019390 
Message accepted for delivery)
Jun 14 11:47:45 bq0 sendmail[19391]: j5EFljEW019390: to=admin, 
delay=00:00:00, xdelay=00:00:00, mailer=local, pri=34070, dsn=2.0.0, 
stat=Sent


I did a some googling and found a post
http://forums.fedoraforum.org/showthread.php?t=27608

Any sujestons as what I should do .....I  dont want to play with another 
script to get this done??....thanks in advance

-- 

Best Regards, Jon McCauley