Send email using the GMail SMTP server from a PHP page

Your code does not appear to be using TLS (SSL), which is necessary to deliver mail to Google (and using ports 465 or 587).

You can do this by setting

$host = "ssl://smtp.gmail.com";

Your code looks suspiciously like this example which refers to ssl:// in the hostname scheme.

// Pear Mail Library
require_once "Mail.php";

$from = '<[email protected]>';
$to = '<[email protected]>';
$subject = 'Hi!';
$body = "Hi,\n\nHow are you?";

$headers = array(
    'From' => $from,
    'To' => $to,
    'Subject' => $subject
);

$smtp = Mail::factory('smtp', array(
        'host' => 'ssl://smtp.gmail.com',
        'port' => '465',
        'auth' => true,
        'username' => '[email protected]',
        'password' => 'passwordxxx'
    ));

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

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

Using Swift mailer, it is quite easy to send a mail through Gmail credentials:

<?php
require_once 'swift/lib/swift_required.php';

$transport = Swift_SmtpTransport::newInstance('smtp.gmail.com', 465, "ssl")
  ->setUsername('GMAIL_USERNAME')
  ->setPassword('GMAIL_PASSWORD');

$mailer = Swift_Mailer::newInstance($transport);

$message = Swift_Message::newInstance('Test Subject')
  ->setFrom(array('[email protected]' => 'ABC'))
  ->setTo(array('[email protected]'))
  ->setBody('This is a test mail.');

$result = $mailer->send($message);
?>