I've recently installed Zimbra 6.0 network edition on CentOS 5.4. Currently the server is sitting inside the network with an internal IP. However, I will be moving it to our DMZ, which sits between 2 firewalls and giving it a static public IP. Mail will be stored locally on the same box. Users will primarily access email via the web client, although there will be 20 or so (out of 150) users who will use Outlook and connect via IMAP.
I followed the install instructions for CentOS found on howtoforge. I'm concerned that I've got all security turned off on the box right now per those instructions. Does anyone have any advice on locking it down a bit more while on the DMZ?
Thanks in advance!