

Once in the blue moon, you should check your Spam folder to see if there is a non-spam email was sent to you, but be careful of scam mails.

With the smart security policy and technology of Gmail in the present, emails that sent to your Inbox will be devided into three tab: Primary, Social and Promotions and most of scam, spam email will be moved to spam folder, but they may be mistaken sometimes it happened to me when I registered at a website and my confirmation mail is moved to Spam folder, makes me think the website don't let me sign up.
