Indeed, however if you're running your own server(s) then firewalls/monitoring/IDS/etc... need to be part of your typical setup anyhow. I wouldn't suggest some

Indeed, however if you're running your own server(s) then firewalls/monitoring/IDS/etc... need to be part of your typical setup anyhow. I wouldn't suggest someone who doesn't admin their own servers to get a server for running mail on, but if you manage/secure/backup servers for other stuff, mail is pretty easy to do.