Spam comming from 127.0.0.1 getting to deffered messages.

[don.hess]

Here is our set up for reference:

Multiple WAN IPs -> Switch --> Firewall 1 (LAN) --> Workstations
                           --> Firewall 2 (DMZ) --> Zimbra with firewall on server also

This puts a good firewall between you and the internet for both the LAN and DMZ. Then only open the ports you need for Firewall 2 and also on Zimbra. pfSense has worked for everything I've tried on it. And then figure out why your LAN machines are sending spam.

If you only have one external IP address:

WAN IP --> Firewall 1 (WAN) --> Switch (DMZ) (Zimbra with firewall on server also) --> Firewall 2 (LAN) --> Workstations

[aldennis]

Thanks for the inputs.
I will use the DMZ for syncing with our standby Zimbra server.