How to to send mail using gmail in Laravel?

I try again and again to test sending an email from localhost but I still cannot. I don't know anymore how to do it. I try search to find solution but I cannot find one. I edited config/mail.php:

<?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", "mail", "sendmail", "mailgun", "mandrill", "ses", "log"
    |
    */

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

    /*
    |--------------------------------------------------------------------------
    | 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' => '[email protected]', 'name' => 'Do not Reply'],

    /*
    |--------------------------------------------------------------------------
    | 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'),

    /*
    |--------------------------------------------------------------------------
    | SMTP Server Password
    |--------------------------------------------------------------------------
    |
    | Here you may set the password required by your SMTP server to send out
    | messages from your application. This will be given to the server on
    | connection so that the application will be able to send messages.
    |
    */

    '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',

    /*
    |--------------------------------------------------------------------------
    | Mail "Pretend"
    |--------------------------------------------------------------------------
    |
    | When this option is enabled, e-mail will not actually be sent over the
    | web and will instead be written to your application's logs files so
    | you may inspect the message. This is great for local development.
    |
    */

    'pretend' => false,

];
`

and I edited .env file like this already:

MAIL_DRIVER=smtp
MAIL_HOST=smtp.gmail.com
MAIL_PORT=587
[email protected]
MAIL_PASSWORD=password
MAIL_ENCRYPTION=null

It still produced error like this:

first login to your gmail account and under My account > Sign In And Security > Sign In to google, enable two step verification, then you can generate app password, and you can use that app password in .env file.

Your .env file will then look something like this

MAIL_DRIVER=smtp
MAIL_HOST=smtp.gmail.com
MAIL_PORT=587
[email protected]
MAIL_PASSWORD=apppassword
MAIL_ENCRYPTION=tls

Don't forget to run php artisan config:cache after you make changes in your .env file.

Try using sendmail instead of smtp driver (according to these recommendations: http://code.tutsplus.com/tutorials/sending-emails-with-laravel-4-gmail--net-36105)

MAIL_DRIVER=sendmail
MAIL_HOST=smtp.gmail.com
MAIL_PORT=587
[email protected]
MAIL_PASSWORD=apppassword
MAIL_ENCRYPTION=tls