I just posted a module that allows you to easily create a sign-up list of verified email addresses.

A DotNetNuke portal administrator can place an instance of the module on a page and customize the sign-up message and the email verification message. The captured data can also be exported to Excel.

The module and code are posted here:

http://www.adefwebserver.com/DotNetNukeHELP/Misc/SignUp/