First off I wanna say thank you for this guide. It's exactly what I'm looking for. I got it all setup and working I just need to figure out how to get it into production. Currently we have 2 email servers: 1 exchange with 25 users and 1 postfix/mysql vmail server. I want to have all incoming mail be screened by spamsnake and then have it sent to it's correct destination. When I put this into production, I'm going to take point the MX record and change around the router so that all email will come into the spamsnake server but I have a couple questions first. How does the spamsnake box know how to relay the email to the correct servers? Is it the /etc/postfix/transport map? I am hoping that it looks at /etc/postfix/transport and says, "this email is going to domain1 which is at 192.168.1.2 so I'm going to send it there. And this other email is going to domain2 which is at 10.0.0.2 and I'm going to send that one here" Also I think I figured out how to send all outgoing email through spamsnake on exchange using the SMTP smarthost field but how would one setup postfix to relay all mail through spamsnake first?