EFW Support

Hi all,

Currently i have Firewall Mail Server (1 box) and Exchange Server 2007 Standard without edge transport (1box), i don't have mail filtering for spam and virus, so a lot of spam access to exchange server and all the clients get mad.
Current topology: (total 2 firewall boxes and one exchange server box)

internet --> firewall proxy server (2 nic, public 124.xx.xx.18 and private 10.0.0.254) --> clients (block all incoming and allow all outgoing)
email --> firewall mail server (2 nic, public 124.xx.xx.19 and private 10.0.0.253) --> exchange server (10.0.0.252) --> clients  (only open port 25 and 443)

I am planning to replace only my current firewall mail server to Endian Firewall Community 2.3 as a mail gateway server+firewall server in one box, I am new in here, may i ask a few questions please:

1. Is it possible to use Endian Firewall Community 2.3 as a firewall server and mail gateway (filter spam and virus) in one box?
2. What packages / services, i need to install on Endian Firewall Community 2.3 for firewall mail server? (without proxy server because i already have it)
3. currently i have 2 public ip (one for firewall proxy server and the other for firewall server mail), is it ok if i have 2 firewall in one LAN?
4. is there any how to for install Endian Firewall Community 2.3 for exchange server 2007 for my scenario?
Thank you and please CMIIW with my topology!