Have you checked your Email Spam folder or any Spam/Virus firewall your computer may be running on? If your computer is on an office network, these Spam blockers can be strict at times.
Notification emails are sent from "noreply@TrackSmart-emails.com," so make sure you have that email address added to your safe sender list (i.e., whitelist the @tracksmart-emails.com domain).
Is this issue happening for all employees or is only one being singled out? Which employees have you experienced this with.