Current setup
First of all i must say that im so so (read like "nothing know") in things like postfix or open dkim.
We have many domains on our exchange (realy a lot). and thats work like "enternet -> firewall -> mail gateway -> exchange's -> mail gateway -> firewall router-> enternet"
In that case all of oure domains sends from 1 ip(thats not be good). Now we whant to send those mails from they own ip's (1 domain - 1 ip, we already have them a lot). Our netops engeneers say that the can separate outgoing traffic (read like our mails) by ports that "mail gateway" connect to firewall router, and route it to another outgoing ip. BUT our mail gateway cant do it and connect to router trought 1 standatd port.
I'l start googled and found that postfix can fo it and separate thise by field "from" and relay it with another port. BUT we whant to signing it with dkim and i think postfix + openDKIM can do it.
At the end. Outgoing mail way see like thise "Exchange -> postfix+opendkim(example.com goin in 10.10.10.2:2555,example.uk going in 10.10.10.2:2556 adn etc) -> router (separate each traffic by connecting port ?) -> enternet"
Inboud way didnt change.
And a question! Can someone help and write commands to configure postfix + opendkim (or mb another freeware product). Or link a guide thats allready have in www.
P.S. I found guide ( only for postfix) link. But here didnt tell us how install postfix and what choose we must take on each setup page.
