There are known problems with Hotmail and Yahoo mail. Sometimes the mail is refused completely and you will never receive it and other times it is directed to the junk/bulk folders.
The activation email is normally sent immediately, give or take a few minutes, via an automated system. This can cause some 'over aggressive' email spam filters to receive the email and class it as spam or junk mail – please check your spam, junk or bulk email boxes.
If you have still not received any email(s) we suggest you click "Didn't receive your confirmation email?" in the login screen. If that fails we suggest you consider using an alternative email address.