This is most likely because you are using a free email service (such as Hotmail) and these systems can delay or not relay your confirmation message due to:

• difficulties when your free email account has reached it's message or traffic limit
• problems with overloading
• slow service or lost emails due to the unguaranteed service nature of free services

If you're not using a free email service and still haven't got your message after a number of hours, please check your email address was correctly entered and is working, and resend the confirmation code