Web mailing lists

Hi,

I need to setup a system where users can go to a webpage and automatically subscribe/unsubscribe to any of a dozen or so email newsletters. I also need a database of email addresses in order to send out the newsletters, once, possibly twice amonth. It would also be great if bounced email addresses could be auto deleted as well.

Anyone know the best (easiest, cheapest) way to go about setting up something like this?

Thanks.