mail() problem, please help - URGENT

[chacho]

hi guys,
i need help on this one. i am trying to send plain text mail with php and on some/most servers it simply does not get through- the mail gets rejected as bad mail or something (but not as spam). i have tried anything i could find on the internet but no luck till now.
i tried just mail($to,$subject, $msg)
the same thing but with $headers-
tried most of them in many kinds of orderings,
with or without spaces/crlf/lf and so on
i tried the pear mail class- with smtp and sendmail
and nothing seems to work.
here's some code

include('Mail.php');

$recipients = '[e-mail]';

$headers['MIME-Version']    = '1.0';
$headers['Content-Type']    = 'text/plain; charset="iso-8859-1';
$headers['From']    		= '[e-mail]';
$headers['To']      		= '[e-mail]';
$headers['Reply-To']   		= '[e-mail]';
$headers['X-Mailer']   		= 'PHP';

$headers['Subject'] 		= 'Test message';

$body = 'Test message';

//	for 'smtp'
$param["host"]	= 'localhost';
$param["port"]	= 25;
$param["auth"]	= false; 

//	for 'sendmail'
	$params['sendmail_path'] = '/usr/sbin/sendmail';
//	$params['sendmail_path'] = '/usr/sbin/sendmail -t -i -F [email][e-mail][/email] -f [email][e-mail][/email]';

// Create the mail object using the Mail::factory method
$mail_object =& Mail::factory('sendmail', $params);
$result = $mail_object->send($recipients, $headers, $body);
if($result) echo 'ok'; else echo PEAR_Error::toString();

$mail_object =& Mail::factory('smtp', $param);
$result = $mail_object->send($recipients, $headers, $body);

if($result) echo 'ok'; else echo PEAR_Error::toString();

$headers  = "From: [email][e-mail][/email]\n"; 
$headers .= "Reply-To: [email][e-mail][/email]\n"; 
$headers .= "X-Priority: 3\n"; 
$headers .= "X-Mailer: PHP Mailer\n"; 

$result = mail('[e-mail]', 'test mail', 'msg', $headers);
if($result) echo 'ok'; else echo 'error';