I want to be able to have a simple signup module where the web visitor only needs to enter their e-mail address once and they are automatically added to one of my specific CC list without having to do anything else.
This is certainly something that can be done using our API. However, this would require some programming experience from either yourself or someone else in order to implement. We do offer some sample sign up forms in C#, PHP, and ColdFusion available here.
If you do not have any programming experience, I would recommend taking a look at our Development Resources, which has a list of 3rd party vendors that have experience working with our API. I would also recommend taking a look at our Rest API Documentation which has how-to guides for our API.
I hope this helps get you started. Please feel free to post on this forum with any questions that you may have.