delay() notification seems not working

I am following this to delay notification. http://ift.tt/2fqkAFY

From localhost, I tried to send notification with Gmail credentials. It sends email but sends immediately and also it takes around 10 seconds to send email. My code is below.

$when = \Carbon\Carbon::now()->addMinutes(10);

$user->notify((new Notification($notification))->delay($when));

Was that due to Gmail or I missed something?

via Chebli Mohamed