// Default transport (can be sendmail, smtp, file or memory)
'transport' => 'sendmail',
'name' => 'localhost.localdomain',
'connection_class' => 'plain',
'path' => DATA_PATH . 'mail/',
'callback' => static function (FileTransport $transport) {
return 'Message_' . microtime(true) . '_' . mt_rand() . '.txt';