email using PEAR

I grabbed the following script from a website and installed the
Socket.php file in the /usr/share/pear/Net directory on a RH 8.0 Linux
box. When I run the script it displays the "Mail sent" message but no
mail actually arrives in my mailbox.

include("Mail.php");

$recipients = "brunowright@yahoo.com";

$headers["From"] = "brunowright@yahoo.com";
$headers["To"] = "brunowright@yahoo.com";
$headers["Subject"] = "Test message";

$body = "TEST MESSAGE!!!";

$params["host"] = "my.smtp.server";
$params["port"] = "25";
$params["auth"] = true;
$params["username"] = "myusername";
$params["password"] = "mypassword";

// Create the mail object using the Mail::factory method
$mail_object =& Mail::factory("smtp", $params);

$mail_object->send($recipients, $headers, $body);

echo "Mail has been sent!!\n";

?>

I was told that it was much easier to use PEAR than to try setting up
sendmail on my system.

Any comments would be greatly appreciated.

David