迅捷库无法发送消息

Question

我正在使用swiftlibrary，但是我无法发送消息，请为此提供帮助

require_once（APPPATH.'libraries / swiftmailer / lib / swift_required.php'）;

    $transport = Swift_MailTransport::newInstance();
    $message = Swift_Message::newInstance();


    $message->setSubject('Your subject')
    ->setFrom('abc@gmail.com')
    ->setTo('xyz@gmail.com')
    ->setBody('Here is the message sent with swiftmailer')
    ->addPart('<q>Here is the message sent with swiftmailer</q>', 'text/html');


    $mailer = Swift_Mailer::newInstance($transport);
    $result = $mailer->send($message);

    if($result)
    {
        echo "Email sent successfully";
    }
    else
    {
        echo "Email failed to send";
    }