Laravel 5.8 stopped sending email

Sending emails from my system has stopped working at all. .env settings are ok. I tried to run this code to test:

php artisan tinker

Mail::getSwiftMailer()->registerPlugin (
    new Swift_Plugins_LoggerPlugin(new Swift_Plugins_Loggers_EchoLogger(false))
);
$to = 'youraddress@example.com';
Mail::raw('Testmail', function ($message) use($to) {  
    $message->to($to)->subject('Testmail'); 
});

and I'm getting this error:

PHP Warning:  stream_socket_client(): php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution in /home/usuario/dev/dev-contaja/vendor/predis/predis/src/Connection/StreamConnection.php on line 127
PHP Warning:  stream_socket_client(): unable to connect to tcp://redis:6379 (php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution) in /home/usuario/dev/dev-contaja/vendor/predis/predis/src/Connection/StreamConnection.php on line 127
Predis/Connection/ConnectionException with message 'php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution [tcp://redis:6379]'

I'm using use docker.

via Chebli Mohamed