One of my customer is having one Head Office and a Branch. Each location will have one Exchange 2003 Back-End and one Front-End. I want to keep exchange servers in 2 different Routing Groups as physically there are connected through WAN links. OWA site will be published on the ISA 2004 server which will be acting as internal firewall.
To make both sites as failover site for each other I would like do the following things:
#Create MX record (10) of Front-End01 pointing to mail.domain.com in Head Office. (Primary)
#Create MX record (20) of Front-End02 pointing to mail.domain.com in Branch Office. (Secondary)
If the mails cannot be delivered to via Front-End01, then the mails automatically delivered to Front-End02.
Q1) I would like to know, under what circumstances and conditions the mails are sent to Front-End02 (secondary) instead of Front-End01 (primary)?
Q2) Do I need to setup the OWA on both the locations and publish on the ISA 2004 on both the locations?
Q3) What settings should I do on the Back-End servers to deliver the mails internally between routing groups?
Q4) Any other suggestion based on the above scenario to make complete redundancy?
I am badly in need of your suggestions.