It makes sense to look the missing email up in the “Spam” section in your email. Also in Gmail it would be a good idea to check the “All mail” and “Promotions” folders. Please make sure that HitBTC addresses (@hitbtc.com) are not blacklisted in your email settings.
If that doesn’t help, please contact our support team. They will be glad to resend your email to you, or solve the problem in any other suitable way.