I’m running Exchange 5.5 SP4 on Windows NT 4 SP6. I will be installing Exchange 2003 on a server at a remote site. Even though I will be upgrading the older Exchange to the latest version, that won’t be happening for at least 4 months. In the interim, is it possible to connect Exchange 2003 to Exchange 5.5 via a secure connection via the Internet? At present all incoming and outgoing mail must pass through our Exchange 5.5 box. Is it also possible to move user mailboxes at the remote site to what will be their Exchange 2003 server; direct incoming mail destined for a mailbox on the remote server to that server; and configure the Exchange 2003 server to send mail to the Exchange 5.5 server when trying to be delivered outside our organization?
– Via the Internet
This is possible. I can give you a thumbnail sketch of what you will need to look at; a more detailed response will take more space than I have. You can connect different versions of Exchange. I did this for a company several years ago. Since you’re dealing with two different locations, you’ll want to think about reflecting this in your Exchange setup by putting the new server in another Exchange site so it can operate independently of the other server if the link is down for any reason. Since you are moving users from one version of Exchange to another and essentially skipping a version in the process, you will want to export the users’ e-mail from Exchange 5.5, copy the file onto the Exchange 2003 server and then import the mail to the server on the remote end after creating the mailbox for the user.
Since all e-mail must pass through the Exchange 5.5 server, you can forward the undeliverable e-mail to the second server. You will want to look into the Exchange administration program for 5.5 and look for an option that will forward all undeliverable mail to another server. Enter the IP address for the Exchange 2003 server in the appropriate field, and you should get e-mail for a given user to the correct server. Look closely at the VPN link you’ll be using to connect the two servers. Depending on how fast the connection is between locations, you may need to help each side out a little bit. When I set up a multisite mail setup, I found I had to use WINS at each location to help the Exchange 5.5 server find the information it needed at the other end of the connection.
When you get ready to upgrade your Exchange 5.5 server to 2003, you will look to do something similar to what you’re doing for the first upgrade, in terms of the steps involved. I would strongly suggest that you set up a second server at the Exchange 5.5 location and migrate users to that one at a time. This will allow you to keep things running with minimal disruptions in e-mail service.
