laravel 5.4: sending email from localhost not working

I want to sent emails from my localhost with laravel 5.4. It is showing me the following error: screenshot of the error

This is my .env file

MAIL_DRIVER=smtp
MAIL_HOST=smtp.gmail.com
MAIL_PORT=587
MAIL_USERNAME=myemail@gmail.com
MAIL_PASSWORD=mypassword
MAIL_ENCRYPTION=tfl

This is my mail.php file

<?php

return [

    /*
    |--------------------------------------------------------------------------
    | Mail Driver
    |--------------------------------------------------------------------------
    |
    | Laravel supports both SMTP and PHP's "mail" function as drivers for the
    | sending of e-mail. You may specify which one you're using throughout
    | your application here. By default, Laravel is setup for SMTP mail.
    |
    | Supported: "smtp", "sendmail", "mailgun", "mandrill", "ses",
    |            "sparkpost", "log", "array"
    |
    */

    'driver' => env('MAIL_DRIVER', 'mail'),

    /*
    |--------------------------------------------------------------------------
    | SMTP Host Address
    |--------------------------------------------------------------------------
    |
    | Here you may provide the host address of the SMTP server used by your
    | applications. A default option is provided that is compatible with
    | the Mailgun mail service which will provide reliable deliveries.
    |
    */

    'host' => env('MAIL_HOST', 'smtp.gmail.com'),

    /*
    |--------------------------------------------------------------------------
    | SMTP Host Port
    |--------------------------------------------------------------------------
    |
    | This is the SMTP port used by your application to deliver e-mails to
    | users of the application. Like the host we have set this value to
    | stay compatible with the Mailgun e-mail application by default.
    |
    */

    'port' => env('MAIL_PORT', 587),

    /*
    |--------------------------------------------------------------------------
    | Global "From" Address
    |--------------------------------------------------------------------------
    |
    | You may wish for all e-mails sent by your application to be sent from
    | the same address. Here, you may specify a name and address that is
    | used globally for all e-mails that are sent by your application.
    |
    */

    'from' => [
        'address' => env('MAIL_FROM_ADDRESS', 'myemail@gmail.com'),
        'name' => env('MAIL_FROM_NAME', 'Example'),
    ],

    /*
    |--------------------------------------------------------------------------
    | E-Mail Encryption Protocol
    |--------------------------------------------------------------------------
    |
    | Here you may specify the encryption protocol that should be used when
    | the application send e-mail messages. A sensible default using the
    | transport layer security protocol should provide great security.
    |
    */

    'encryption' => env('MAIL_ENCRYPTION', 'tls'),

    /*
    |--------------------------------------------------------------------------
    | SMTP Server Username
    |--------------------------------------------------------------------------
    |
    | If your SMTP server requires a username for authentication, you should
    | set it here. This will get used to authenticate with your server on
    | connection. You may also set the "password" value below this one.
    |
    */

    'username' => env('MAIL_USERNAME'),

    'password' => env('MAIL_PASSWORD'),

    /*
    |--------------------------------------------------------------------------
    | Sendmail System Path
    |--------------------------------------------------------------------------
    |
    | When using the "sendmail" driver to send e-mails, we will need to know
    | the path to where Sendmail lives on this server. A default path has
    | been provided here, which will work well on most of your systems.
    |
    */

    'sendmail' => '/usr/sbin/sendmail -bs',

    /*
    |--------------------------------------------------------------------------
    | Markdown Mail Settings
    |--------------------------------------------------------------------------
    |
    | If you are using Markdown based email rendering, you may configure your
    | theme and component paths here, allowing you to customize the design
    | of the emails. Or, you may simply stick with the Laravel defaults!
    |
    */

    'markdown' => [
        'theme' => 'default',

        'paths' => [
            resource_path('views/vendor/mail'),
        ],
    ],

];

This is my mail class in App\mail\ directory

<?php

namespace App\Mail;

use Illuminate\Bus\Queueable;
use Illuminate\Mail\Mailable;
use Illuminate\Queue\SerializesModels;
use Illuminate\Contracts\Queue\ShouldQueue;

class CompanyVerificationEmails extends Mailable
{
    use Queueable, SerializesModels;

    /**
     * Create a new message instance.
     *
     * @return void
     */
    public function __construct()
    {
        //
    }

    /**
     * Build the message.
     *
     * @return $this
     */
    public function build()
    {
        return $this->view('emails.comp_ver_emails');
    }
}

This is my controller

<?php

namespace App\Http\Controllers;

use App\General_model;

use App\Http\Requests;

use Session;

use Mail;
use App\Mail\CompanyVerificationEmails;

use Illuminate\Http\Request;

use App\Http\Controllers\Controller;

use Illuminate\Foundation\Validation\ValidatesRequests;

use Illuminate\Foundation\Auth\Access\AuthorizesRequests;

use Illuminate\Foundation\Auth\Access\AuthorizesResources;


class General_controller extends Controller
{

public function sentemail()
{
     $mail_to = 'receiver_email@gmail.com';

     Mail::to($mail_to)->send(new CompanyVerificationEmails);

     dd('Mail send successfully');
}

}

via Chebli Mohamed