mail.php

<?php

if(isset($_POST['email'])) {
    // Require the Swift Mailer library
    require_once 'lib/swift_required.php';

    $transport = Swift_SmtpTransport::newInstance('mail.dominio.com.br', 25, 'tls' )
      ->setUsername('mail@dominio.com.br')
      ->setPassword('54321')
      ;


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


    // Creating the message text using fields sent through POST

    foreach ($_POST as $key => $value)
        $messageText .= ucfirst($key).": ".$value."\n\n";




    // You can change "A message from Pivot Template Form" to your own subject if you want.
    $message = Swift_Message::newInstance('Coronel David - Mensagem enviado pelo site')
      ->setFrom(array($_POST['email'] => $_POST['name']))
      ->setTo(array('contato@dominio.com.br' => 'Coronel David'))->setBody($messageText);
//                           ^                    ^
//       Your email address_/          Your name_/



    // Send the message or catch an error if it occurs.
    try{
        echo($mailer->send($message));
    }
    catch(Exception $e){
        echo($e->getMessage());
    }
    exit;
}

?>