I am getting error about email in Laravel project - laravel

Question

I have a problem to solve. However, this problem came to me from sentry.io. So I didn't see the problem directly.
The problem is as follows: Address in mailbox given [] does not comply with RFC 2822, 3.6.2.
enter image description here
The problem with sentry.io is in the picture. However, as far as I understand, the problem is not directly caused by this file. In other words, the problem is in sending mail, so since email is used here, it shows the problem here. I have not used services such as laravel mailing before, so I have no idea right now.
I can share with you the necessary codes, files, etc., so that we can better understand the problem.

Answer 1

Send Mail
Mail::to($user->email)->send(new NothingListenedFor3Days($user));
Mail Class
<?php
namespace App\Mail;
use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Mail\Mailable;
use Illuminate\Queue\SerializesModels;
class NothingListenedFor3Days extends Mailable
{
use Queueable, SerializesModels;
protected $user;
/**
* Create a new message instance.
*
* #return void
*/
public function __construct($user)
{
$this->user = $user;
}
/**
* Build the message.
*
* #return $this
*/
public function build()
{
return $this->subject('Your Subject')
->view('Your blade file path')->with('user',$this->user);
}
}
For reference link

Answer 2

#Ali Raza
I made both files as I shared below. Are there any mistakes I've made?
EmailCronJobController.php
Mail::to($user->email)->send(new NothingListenedFor3Days($user));
NothingListenedFor3Days.php
namespace App\Mail\Listener;
use App\Course;
use App\User;
use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Mail\Mailable;
use Illuminate\Queue\SerializesModels;
class NothingListenedFor3Days extends Mailable
{
use Queueable, SerializesModels;
public $listener;
public $random_contents;
public $fromEmail = 'listener#omnicourse.io';
public $fromName = 'Omnicourse';
/**
* Create a new message instance.
*
* #return void
*/
public function __construct(User $listener)
{
$this->listener = $listener;
$this->random_contents = Course::all()->random(10);
}
/**
* Build the message.
*
* #return $this
*/
public function build()
{
return $this->from($this->fromEmail,$this->fromName)
->view('email.listener.nothing_listened_for_3_days')->with('user',$this->listener);
->text('email.listener.nothing_listened_for_3_days_plain')
->subject("Let's move ahead together");
}
}