laravel Process could not be started [Le chemin d'acc�s sp�cifi� est introuvable. when send mail

I use flutter for developement mobile application and in backend I use laravel, now when I try to register user then send mail I found this error in send mail.

Process could not be started [Le chemin d'acc�s sp�cifi� est introuvable.

code .env:

MAIL_DRIVER= smtp
    MAIL_HOST=smtp.gmail.com
    MAIL_PORT=465
    MAIL_USERNAME=my gmail
    MAIL_PASSWORD=my password
    MAIL_ENCRYPTION=tls
    MAIL_FROM_ADDRESS=my gmail
    MAIL_FROM_NAME="${APP_NAME}"

code mail.php:

         'mailers' => [
            'smtp' => [
                'driver' => env('MAIL_DRIVER', 'smtp'),
                'transport' => 'mail',
                'host' => env('MAIL_HOST', 'smtp.googlemail.org'),
                'port' => env('MAIL_PORT', 587),
                'encryption' => env('MAIL_ENCRYPTION', 'tls'),
                'username' => env('MAIL_USERNAME'),
                'password' => env('MAIL_PASSWORD'),
                'timeout' => null,
                'auth_mode' => null,
            ],

            'ses' => [
                'transport' => 'ses',
            ],

            'mailgun' => [
                'transport' => 'mailgun',
            ],

            'postmark' => [
                'transport' => 'postmark',
            ],

            'sendmail' => [
                'transport' => 'sendmail',
                'path' => '/usr/sbin/sendmail -bs',
            ],

            'log' => [
                'transport' => 'log',
                'channel' => env('MAIL_LOG_CHANNEL'),
            ],

            'array' => [
                'transport' => 'array',
            ],
        ],

how to resolve this error and thanks.

via Chebli Mohamed