In our test lab we have one Exchange Server 2003, (Exchange1), behind a firewall which works fine.
However I want another server to accept incoming mail so if our exchange box goes down it will still collect the incoming e-mail and hold it until the exchange e-mail box comes back on line then passes it to the Exchange Box, (Exchange1), which in turn delivers it to the correct mail box.
I know I need to create another MX record with a higher cost but what do I need to achieve my result ? Do I need just another exchange box, or can I use SMTP and IIS on a 2003 server ? Pointers and advice would be very much appeciated.