That sounds pretty cool! I suppose that if you keep the original email in the database you could have an online archive as well!
I assume you mean to enter a message via a form on the WWW and then it gets emailed out to the list?
So, is there a way to take an email and then enter it into the above instead of using a form? Maybe even using a POP3 account and deleting the message from the POP3 when finished. That way it just sends the message once, but would save it for archive.