On 2014-08-13, Timothy Murphy <gayleard at alice.it> wrote: > > I seem to recall that you have very occasionally made helpful suggestions - > maybe I am confusing you with someone else. I am somewhat mortified that you are not applying Occam's razor here. If you believe that I have been helpful in the past, isn't the simplest explanation that it's possible I'm being helpful now? (Whether I actually have been helpful is in the eye of the beholder; I like to believe it myself, but that's pure conceit.) > I give you the same answer - if you believe the TASK of postfix > is difficult to understand, explain why. It is difficult to understand because two of postfix's primary tasks are to implement SMTP and deliver mail safely. Both of these tasks are themselves difficult to do well, especially SMTP, a service widely targeted by attackers which offers little in the way of authentication. > BC hasn't answered this, and I very much doubt if KK will either. We both did; don't blame us if you didn't like the response. > As I see it, the principal task of postfix is to take in email > arriving at port 25, and convey it to one or more destinations. There are *so* many details that you ignore in this gross oversimplification. The most dangerous one is, what mail do you accept, and what mail are you willing to convey? One mistake in this area and you become a spam relay. > In my experience email has been working without problems > for as long as Unix has been running, This is patently untrue. Here's just one example: https://en.wikipedia.org/wiki/Morris_worm > It is not necessary to understand how the internal combustion engine works > in order to drive a car; and there is no evidence that those who do know > make better drivers. In this analogy, drivers == email users. If you are running an SMTP server, you're a mechanic, *not* a driver! If you don't want to understand how a car works, you shouldn't be a mechanic. --keith -- kkeller at wombat.san-francisco.ca.us