Make sure that you add the new domain name to a policy in the Exchange System Manager’s Recipient Policies container. This can be your default policy, or you can create a new one.

Make sure that whoever is hosting your public DNS adds an MX record for the new domain and points it at your exchange server’s public IP (or hopefully your SMTP relay host’s IP address!)

As for the second part… Active Directory does not have Primary Domain Controllers and Backup Domain Controllers. It is a multi-master topology – so all domain controllers have a read/write copy of the directory database. You do however have FSMO roles… one of which is the PDC emulator.

Anyway – it sounds to me like you have a pretty small network – so I would not worry about installing Exchange on a second system…. especially if your system is another DC.

Having 2 systems configured as domain controllers is good for any sized network. Make sure that each DC is running DNS & WINS, and make sure they are both Global Catalog Servers. It is also not a bad idea to have both running DHCP – but *make sure* that you split your scope up so that you do not have any overlap! This is handy if you have one of your 2 server systems go down – you will still have all of your basic infrastructure functioning as it should.

Now – for Exhcange redundancy… if you have the money for the licensing costs and hardware costs, a 2nd installation of Exchange with DoubleTake is great. However, for a small network, I might suggest that you stick with the single install and just make sure that you have your backup and restore process well documented. If you have a couple of old workstation systems, you could even set them up as a test network and practive your recovery process there. In addition to making you more prepared for an actual event, you will also be testing the integrity of your backup media which is more valuable than you know…

Put together a basic DR kit. Instructions on how to do the entire restore process, all required software media, all required lic keys, all required information, like domain names, org names, etc., unattended answer files, phone numbers to people who can help, etc…

If you want to use something like Ghost to enhance your backup routines, that is great – just make sure that you do not install the Ghost client on any servers with hardware or software RAID configs… (trust me). Taking a monthly backup image of a system can be very useful in speeding up recovery times.

Now – when you use the *Exchange version* of AD Users and Computers… are you running that from the 2nd Domain Controller or from your Workstation? (You did install the Exhcange Management Tools on your workstation, right?)

Best of luck…
—
David Levine