LinuxQuestions.org - PHP mail not connecting to SMTP server but can connect with telnet

Hi everbody.

I've scoured google for any hint of what I might be doing wrong to no avail!

I have been using the PHP mail() function quite happily for a while but I want to send mail via an SMTP server, either installed on another box or a remote one(eg ISP's server).

I get an error "unable to connect to smtp server etc etc"

The weird thing is that I can connect to which ever smtp server I'm try in the script with telnet so I know that port 25 isn't being blocked by my ISP.

The script I'm using is very simple, using the Pear mail package pretty much like this:

<?php
require_once "Mail.php";

$from = "Sandra Sender <sender@email.com>";
$to = "Ramona Recipient <reciever@email.com>";
$subject = "Hi!";
$body = "Hi,\n\nHow are you?";

$host = "smtp.host.com";
//$port = 25; default 25
$username = "username";
$password = "password";

$headers = array ('From' => $from,
'To' => $to,
'Subject' => $subject);
$smtp = Mail::factory('SMTP',
array ('host' => $host,'port' => $port,
'auth' => true,
'username' => $username,
'password' => $password) );

$mail = $smtp->send($to, $headers, $body);

if (PEAR::isError($mail)) {
echo("<p>" . $mail->getMessage() . "</p>");
} else {
echo("<p>Message successfully sent!</p>");
}
?>

Is there any other files like hosts or network etc that could affect this?

Maybe I should just start from scratch again?

Any help would be greatly appreciated!!