Originally posted by: clamum
Are you familiar with PHP (or other scripting language) already?
Depending on how many features you need, it would be fairly easy to create a simple one. Here's a tutorial using PHP with MySQL to store the email addresses. If you don't have access to a MySQL database, you can store the address in a simple text file. This tutorial shows part of the text file route.
Originally posted by: Decoy84
So a discussion list and the option for members to create their own email accounts under your domain is what your looking for? Seems like two fairly general and easily locatable scripts you'd need here so i bet you could just pull them for free from a scripts site. Just get a lil specific on your purpose and goals of this and I'll see what I can help hook up.