how secure is ISPConfig on a public IP address?
We will probably be moving our email server from an internal IP to an external/public IP today due to a change in our ISP. Instead of the headaches of trying to configure a one-to-one NAT on our Sonic wall with the Enhanced OS, I figure it would just be easier to put the email server outside the firewall and give this a seperate IP address. NetSol handles our DNS, so I'll make the appropriate changes to our A records.
My question is, is there any security concerns going from an internal to a public IP address. What does the firewall function of ISPConfig filter out?
Thanks in advance for any and all replies.