PHP Fatal error:  Uncaught exception 'Swift_TransportException' with message 'Failed to authenticate on SMTP server with username "xxx@gmail.com" using 2 possible authenticators' in /home/TestMail/SwiftMail/lib/classes/Swift/Transport/Esmtp/AuthHandler.php:171
Stack trace:
/home/TestMail/SwiftMail/lib/classes/Swift/Transport/EsmtpTransport.php(289): Swift_Transport_Esmtp_AuthHandler->afterEhlo(Object(Swift_SmtpTransport))
/home/TestMail/SwiftMail/lib/classes/Swift/Transport/AbstractSmtpTransport.php(114): Swift_Transport_EsmtpTransport->_doHeloCommand()
/home/TestMail/SwiftMail/lib/classes/Swift/Mailer.php(76): Swift_Transport_AbstractSmtpTransport->start()
/home/TestMail/testmail.php(73): Swift_Mailer->send(Object(Swift_Message))
thrown in /home/TestMail/SwiftMail/lib/classes/Swift/Transport/Esmtp/AuthHandler.php on line 171

$transport = Swift_SmtpTransport::newInstance('smtp.gmail.com', 465, 'ssl')

<?php
require_once 'SwiftMail/lib/swift_required.php';
// Create the Transport
$transport = Swift_SmtpTransport::newInstance('smtp.gmail.com', 465, 'ssl')
  ->setUsername('xxx@gmail.com')
  ->setPassword('xxx');

// Create the Mailer using your created Transport
$mailer = Swift_Mailer::newInstance($transport);

$htmlbody = 'some html here';

// Create a message
$message = Swift_Message::newInstance('without head')
    ->setFrom(array('<from email>' => '<some sender>'))
    ->setTo(array('<to email>' => '<some recepient>'))
    ->setBody($htmlbody, 'text/html');

// Send the message
$result = $mailer->send($message);

var_dump($result);
?>

xxx@gmail.comm
             ^