Sometimes membes don't always get their activation email. This happens due to accidental deletion, your junk folder etc.

To Resendthe account activation email:

1. Go here: Blizzard Sector - Diablo 3, Starcraft II, WoW, Diablo 2, Trading, Downloads, Editors, Items, Forums - Email Activation Codes
2. Enter the email address you used when you signed up and click "Email activation codes"
3. When the email arrives in your inbox, be sure to click the link to activate your account.