send_gmail.php

<?php
require_once "Mail.php"; // Make sure that you have pear/Mail and pear/Net_SMTP installed 

$auth_data = array(
        'username' => '<your_login>@gmail.com',
        'password' => '<your_pass>'
);

function send_gmail($auth_data, $to, $subject, $body)
{
    $headers = array(
            'From' => $auth_data['username'],
            'To' => $to,
            'Subject' => $subject
            );

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

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

    if (PEAR::isError($mail))
    {
        throw new DomainException($mail->getMessage());
    }
}

function print_help_and_exit($progname)
{
    echo("Usage: $progname <mailto> <subject>\n");
    echo("Reads the message from stdin and sends to specified mailto\n");
    exit(-1);
}

if(count($argv) != 3)
{
    print_help_and_exit($argv[0]);
}

$input = file_get_contents("php://stdin");
send_gmail($auth_data, $argv[1], $argv[2], $input);
?>