Well, let me tell you about qmail. Each part of that setup has only privilege that it needs to go it's job. Seems a good design and very few problems given its

Well, let me tell you about qmail. Each part of that setup has only privilege that it needs to go it's job. Seems a good design and very few problems given its age. Postfix seems next best by design. How many parts of least privilege is message acceptance to mailbox in exchange? I suspect one program image.