How to fix Swift_TransportException error when sending an email?

Question

Laravel

.env

MAIL_MAILER=sendmail
MAIL_HOST=
MAIL_PORT=
MAIL_USERNAME=null
MAIL_PASSWORD=null
MAIL_ENCRYPTION=null
MAIL_FROM_ADDRESS=null
MAIL_FROM_NAME="${APP_NAME}"

mail.php

'default' => env('MAIL_MAILER', 'sendmail'),
 'sendmail' => [
            'transport' => 'sendmail',
            'path' => '/usr/sbin/sendmail -bs',
        ],

Or is there something I'm not doing right?
Can there be sending emails to laravel via regular mail()