I've recently installed a server (12.04) with Apache, Postfix and Courier. Is this a system you can rely on in a production evinronment? The server (VPS) is hosting both emails and websites. Ref to this guide The thing that worries me the most is, what do I have to do to keep the mail-part up to date? Does this setup require much work in terms of servermanagement? What happens if email falsely gets tagged as spam? How can I undo that?