Currently, we have a Postfix V2.4.5 server with no local accounts receiving email.
We permit internal, local systems to freely use the system as a relay: smtpd_client_restrictions = permit_mynetworks, reject permit_mynetworks mynetworks = 127.0.0.0/8, 295.283.0.0/16, 10.0.0.0/8 (internal subnet obviously obfuscated) In our transport_maps file: ourdomain.org : .ourdomain.org : * smtp:[firewall.ourdomain.org] ---- Ok, now management has asked us to restrict the flow of outbound email (i.e. to the internet) to only selected systems, based on their IP addresses. I'm looking for a general suggestion of how I can implement this selective permit of only certain systems to have emails forwarded out to the internet, with the rest of the systems still able to send email internally via the Postfix-based mail gateway machine. BTW, there is a single network connection on the Postfix box - dual path isn't feasible at this time. Is sender_dependent_relayhost_maps my proper starting point for investigation & experimentation? Thanks, Lee
