I am new here, we will implement Exchange 2007 in our Data center environment, as long as Edge Server does not have security issue because only port 25,443 will open to the DMZ internet firewall. But we have concern for Mailbox server, because Mailbox server will put behind Firewall 3 Server Farm.
What port list have to be opened, since i know that the RPC port is random access from Client / Outlook, is there document for Exchange 2007 Mailbox specify the port to the client? is it the same as Exchange 2003 Back-end server?, we will be facing security issue with security team if many port will be opened from intranet to exchange Mailbox server.
Based on your description it appears you will be firewalling your Exchange server from the internal network? Well, in that case I guess the only ports you need open for client access would be the same ports you'd need open for client access through the internet. To minimize the number of ports that would require you should configure the Outlook clients to use RPC/HTTS. At that point the only port required is 443.