As my co-founder and I finish work on our prototype, we're setting up a closed alpha version that we can invite people to participate in for initial testing. We'd like to have a long list of e-mail addresses, from people wanting to participate, waiting for us when we're ready; so that means updating our neglected holding page with something beautiful, interesting, and presumably containing some kind of "Enter your e-mail address for an alpha invite" form.
Rather than re-invent the wheel, do you have any recommendations for back-end tools meant for this purpose? What's the best way we can gather (opt-in) e-mail addresses from visitors, store them, and then use them later to send out invite codes/links?
Thanks in advance for all recommendations & tips!