I wish I got to work with such cleanly separated systems. 2009/2/28 Iad Scoot <iad.sc...@gmail.com>: > Relay mail directly between all of the internal mail domains (there are > 5) without routing traffic to the Internet.
This will happen automatically if the internal servers are the designated MXes in DNS. If not, as I assume is the case, you can use transport maps to specify that the next-hop for a.com is [internal-host.a.com], or whatever you're using. > Relay mail destined for remote domains that originated from any of the 5 > internal domains to edge Postfix systems. Assuming the internal domain servers are in mynetworks or otherwise appropriately configured, Postfix will accept and forward the mail as expected. > When relaying to the edge Postfix systems, route to the appropriate edge > system based on the sending domain. Sounds like you want sender_dependent_relayhost_maps: http://www.postfix.org/postconf.5.html#sender_dependent_relayhost_maps
