我想问一下如何从Symfony框架（组件symfony邮件程序）发送PHP mail（）。

"symfony/mailer": "5.0.*",

Dsn：

MAILER_Dsn=mail://localhost

控制器方法：

public function test(): Response
{
    $transport = new EsmtpTransport('localhost');
    $mailer = new Mailer($transport);

    $username = $this->getUser()->getusername();

    /** @var Users $user */
    $user = $this->getDoctrine()->getRepository(Users::class)->findOneBy(['username' => $username]);

    if (!$user)
        return new Response("User $username not found! Email not tested.");

    $to = $user->getEmail();

    if ($to) {
            $email = new Email();
            $email->from('test@mydomain.com');
            $email->to($to);
            $email->subject('Test mail');
            $email->text('This is test mail from ... for user ' . $to);
            $mailer->send($email);

            return new Response('Mail send!');
    }

    return new Response('Mail not sent - user email information missing!');
}