Does anyone know of an open source Mandrill clone, preferably self-hosted? Finding someone to do newsletters or simply doing via traditional mailing-list software is pretty easy, but finding an alternative for Mandrill is a bit harder.

We have maybe ten different email templates, in 7 different language. Mandrill makes that sort of easy, but their reason decision to require a Mailchimp account (which we don't need) has made us look for alternatives. We even considered building something in-house, but it seems like something someone else would already have done.