Mailing List Managers?

greyrax asks: "So I'm trying to convince someone to go open source for their list manager. They're about to upgrade to an expensive proprietary solution. With about 400,000 subscribers to this newsletter, a database back-end would certainly be helpful. Bounced address management and easy unsubscribes is important (I've read Smartmail vs. MailMan comparison here). Virtual host support and a web interface are desirable. Any thoughts from the /.ers since this thread last year would be appreciated."