Expected response code 220 but got code "", with message "" it work on php 5.4 but 5.6 show error

Expected response code 220 but got code "", with message "" it work on php 5.4 but 5.6 show error

 hereMAIL_DRIVER=smtp
 MAIL_HOST=smtp.gmail.com
 MAIL_PORT=465
 MAIL_USERNAME=amjad.sarwar23@gmail.com
 MAIL_PASSWORD=*******
 MAIL_ENCRYPTION=null
  return [
   'driver' => env('MAIL_DRIVER',' smtp'),
    'host' => env('MAIL_HOST', 'smtp.gmail.com'),
      'port' => env('MAIL_PORT', 465),
     'from' => ['address' =>"amjad.sarwar23@gmail.com" , 'name' => "amjad"],
    'encryption' => 'tls',
  'username' => env('MAIL_USERNAME'),
 'password' => env('MAIL_PASSWORD'),
 'sendmail' => '/usr/sbin/sendmail -bs',
  'pretend' => false,

    Mail::send('email.verify' , ['confirmation_code' => $confirmation_code],            function($message) use ($abc){
        $message->to(Input::get('email'), Input::get('username'))
            ->subject('Verify your email address');
    });

via Chebli Mohamed