Am 06.12.2013 10:13, schrieb Andreas Kasenides: > The scenario is a classic one: > 1. one or more relay SMTP servers in DMZ > 2. one or more backend SMTP servers on the inside network > 3. There may or may not be separate incoming or outgoing designated SMTP > servers. > > Now the desired functionality is (of course): > 1. relay machines receive messages from outside AND inside > 2. relays check for all the bad things (spam, viruses etc). > 3. for incoming messages relays check for valid local users and reject > messages for invalid users > > Such scenario allows all checks to be done at the entry point allowing > back-ends to > function with the real nice messages and at a much reduced load. > > But there is a problem. If you are a DMZ admin (or a security hawk) #3 > functionality above is > not possible without violating the DMZ policy, especially if you are dealing > with internal LDAP > and DB servers which essentially house personal information. > I am very interested to find out how others deal with this conflict in an > SMTP centric set-up
i would write a script running internally to fetch that list and genereate a static config file for postfix whis is refreshed via cron and copied to the server the list of valid local users typically does not change all day long
