PEAR mail() problem

[NotGiven]

Ok, I THINK I have access to the PEAR packages in my /path/to/pear/...
directory. I tested a simple php page with just :
require("/path/to/pear/Mail.php");
and the page displayed properly so I assume that means my page can see that
directory - I might be wrong.

Here's the code for sending the mail:

$recipients = 'm*@mydomain.com';
$headers['From'] = 'm*@mydomain.com';
$headers['To'] = 'm*@mydomain.com';
$headers['Subject'] = 'Test message';
$body = 'Test message';
$params["host"] = 'smtp.mydomain.com';
$params["auth"] = True;
$params["username"] = 'loginID';
$params["password"] = 'password';
echo 1;
$mail_object =& Mail::factory('smtp', $params);
echo 2;
$mail_object->send($recipients, $headers, $body);
echo 3;

It gets through 2 then does NOT display 3. So, it is not executing the send
command. (I am using smtp mail for a purpose).

How can I test or troubleshoot form this point? Any ideas what is going on
or not going on?

Many thanks!