I run eigenstate.org (and the associated emails) using physical hardware in a colo. OpenBSD's OpenSMTPD makes it relatively easy to set up, although simpler spam filtering would be appreciated.
Nice to know, thank you. As an OpenBSD user, I've thought about going the OpenSMTPD route for a while now, but I've been debating whether to do that or Mail In A Box.
Have you used MIAB at all?