1. Exception info

Swift_TransportException
Expected response code 220 but got code "502", with message "502 Error: command not implemented "

2. Mail Config

return array(
    'driver'     => 'smtp',
    'host'       => 'smtp.exmail.qq.com',
    'port'       => 25,
    'from'       => array('address' => 'admin@mydomain.net', 'name' => 'admin'),
    'encryption' => 'tls',
    'username'   => 'myusername',
    'password'   => 'mypassword',
    'sendmail'   => '/usr/sbin/sendmail -bs',
    'pretend'    => false,
);

3. Code

$data['message'] = 'test';
Mail::send('emails.welcome', $data, function($message)
{
    $message->to('x@qq.com', 'test')->subject('test');
});

How can I solve this problem ?