SMTP Problem

[Opv]

I am trying to test the following simple mail script.

<?php
$to = "[email protected]";
$subject = "Test mail";
$message = "Hello! This is a simple email message.";
$from = "[email protected]";
$headers = "From: $from";
mail($to,$subject,$message,$headers);
echo "Mail Sent.";
?>

But I get the following error:

Mail Sent.PHP Warning: mail(): SMTP server response: 550 Invalid recipient: [email protected] in test3.php on line 7

I have my php.ini file configured to use SMTP port 2525, which is the port used by my mail server,and I have this port assigned as available to my localhost on my router.

Any suggestions?