what do you use for mailing list software?
tdavis: I am a lifetime MailMan advocate.  But you mention tasks that are mostly handled by an MTA (confirmation e-mails, alerts, special offers).  Mailing lists are just that -- mailing lists.  It's not a simple one-to-many delivery service like, say, sending a confirmation e-mail for account creation or sending out alerts to people who subscribe to some kind specific alert.When companies say "sign up for our mailing list" it just means "add your e-mail to a list so we can contact you," it's not an invitation to a discussion group.