Laravel .env constants not working with mail.php - php

Question

The error:
In my mail.php file, if I set
'driver' => env('MAIL_DRIVER'),
and have this to my .env file:
MAIL_DRIVER=log
Then I get the following error:
Swift_TransportException in AbstractSmtpTransport.php line 383:
Expected response code 250 but got code "530",
with message "530 5.7.1 Authentication required"
The wonky work-around
In my mail.php file, I have the following:
'driver' => 'log',
works fine.
The Conclusion
My theory is that mail.php is not reading my .env file constant correctly, since replacing it with the actual string fixes the problem. However, the defaults for this file all make use of .env constants, so I'm wondering why are my .env constants not getting recognized in my mail.php file?
FYI
In other files besides mail.php in the same app, I am using other .env constants that work just fine. For instance, in my UserTableSeeder class, I have:
factory(App\User::class, 1)->create([
'email' => env('ADMIN_EMAIL'),
'password' => Hash::make(env('ADMIN_PASSWORD')),
'is_admin' => 1
]);
which successfully makes use of the below constants from my .env file:
ADMIN_EMAIL=xxxxxxx#yahoo.com
ADMIN_PASSWORD=xxxxxxx
I tried the below 2 php artisan commands (php artisan cache:clear and php artisan config:clear), but "smtp" continued to output when "log" is what I have in my .env file:
04:52:54 Fri May 13 vagrant#homestead (email_notifications) [130]
~/Code/myapp $ php artisan config:clear
Configuration cache cleared!
05:52:56 Fri May 13 vagrant#homestead (email_notifications) [0]
~/Code/myapp $ php artisan tinker
Psy Shell v0.6.1 (PHP 7.0.2-4+deb.sury.org~trusty+1 — cli) by Justin Hileman
>>> dd(env('MAIL_DRIVER'));
"smtp"
>>> exit
Exit: Goodbye.
05:53:23 Fri May 13 vagrant#homestead (email_notifications) [0]
~/Code/myapp $ php artisan cache:clear
Application cache cleared!
05:53:48 Fri May 13 vagrant#homestead (email_notifications) [0]
~/Code/myapp $ php artisan tinker
Psy Shell v0.6.1 (PHP 7.0.2-4+deb.sury.org~trusty+1 — cli) by Justin Hileman
>>> dd(env('MAIL_DRIVER'));
"smtp"

Answer 1

I am not sure whether you have solved it or not yet. But I'll try to provide a way too simple solution.
Short Answer: You need to immediately reboot the application as and when you make changes in your .env file.
Not So Long Answer: It is happening because your .env file is already being accessed by the laravel application. If you make changes in your .env file while your application is running in your local machine, it will not recognize it instantly. You will have to shut down your entire laravel application and reboot it once using $ php artisan serve.
Doing so, it will definitely take up the environment constants and you will get the desired result.
Hope this helps you out. Happy coding. Cheers.

Answer 2

There might be default constants in the .env file that includes one for MAIL_DRIVER=sftp. If you add additional values for the same constant, the FIRST constant is the one that will get defined. Thus, make sure to have just 1 constant definition in your .env file, or at least have it be the 1st one if for some reason you want more than one constant in there.