Sendmail won't submit. Page won't even load. Slim v3.

<?php

<?php
use \Psr\Http\Message\ServerRequestInterface as Request;
use \Psr\Http\Message\ResponseInterface as Response;
require 'vendor/autoload.php';

date_default_timezone_set('America/Los_angeles');

use Monolog\Logger;
use Monolog\Handler\StreamHandler;

// $log = new Logger('name');
// $log->pushHandler(new Monolog\Handler\StreamHandler('app.log', Logger::WARNING));
// $log->addWarning('Zoinks');

// Configure App Settings

$configuration = [
    'settings' => [
        'displayErrorDetails' => true,
    ],
];

$c = new \Slim\Container($configuration);

// Create App
$app = new \Slim\App($c);

// Get container
$container = $app->getContainer();

// Register component on container
$container['view'] = function ($c) {
    $view = new \Slim\Views\Twig('templates', [
        'cache' => false
    ]);

    // Instantiate and add Slim specific extension
    $basePath = rtrim(str_ireplace('index.php', '', $c['request']->getUri()->getBasePath()), '/');
    $view->addExtension(new Slim\Views\TwigExtension($c['router'], $basePath));

    return $view;
};

// Render Twig template in route
$app->get('/', function ($request, $response, $args) {
  return $this->view->render($response, 'about.twig', [
    'name' => $args['name']
  ]);
})->setName('about');

$app->get('/contact', function ($request, $response, $args) {
  return $this->view->render($response, 'contact.twig', [
    'name' => $args['name']
  ]);
})->setName('contact');

$app->post('/contact', function ($request, $response, $args) {
  $body = $this->request->getParsedBody();
  $name = $body['name'];
  $email = $body['email'];
  $msg = $body['msg'];
  $uri = $request->getUri();
  $basePath = $body['index'];

  if(!empty($name) && !empty($email) && !empty($msg)) {
    $cleanName = filter_var($name, FILTER_SANATIZE_STRING);
    $cleanEmail = filter_var($email, FILTER_SANATIZE_EMAIL);
    $cleanMsg = filter_var($msg, FILTER_SANATIZE_STRING);
  } else {
    //message the user that there was a problem
    return $response->withHeader('Location', $uri);
  }
});

// Swiftmailer setup
// Create the Transport
$transport = Swift_MailTransport::newInstance();

// Create the Mailer using your created Transport
$mailer = \Swift_Mailer::newInstance($transport);
// Create a message
$message = Swift_Message::newInstance()
  ->setSubject('Thank you for your input')
  ->setFrom(array($cleanEmail => $cleanName))
  ->setTo(array('devin@devingray.me', 'devin.gray92@gmail.com' => 'Devin Gray'))
  ->setBody($cleanMsg);

// Send the message
if(!$mailer->send($message, $errors)) {
  echo "Error: " . $logger->dump();
} else {
  $result = $mailer->send($message);
}


// After the message sends
if ($result > 0) {
  // send a message that says thank you
  return $response->withHeader('Location', $basePath);
} else {
  // send a message to the user that the message failed to send
  // log that there was an error
  return $response->withHeader('Location', $uri);
}
// Run app
$app->run();