As part of the Exchange Server 2003 Service Pack 1 (SP1) release, Microsoft shipped the Exchange Profile Update tool (aka ExProfRe). If you're familiar with the way Exchange mailbox moves work, you might wonder why a new tool is necessary, and if you aren't using Exchange 2003, you might wonder what the tool is for and whether you'll encounter it if and when you eventually migrate.

Each client profile contains a pointer to its associated mailbox server. Typically, when you launch Outlook, it opens the profile, connects to the mailbox server, and logs on. Messaging API (MAPI) includes a referral mechanism to handle profiles that point to mailboxes that have been moved. When a mailbox has been moved, the server sends back a referral record that tells the client where the mailbox is currently located. The client updates its profile, connects to the new server, and goes about its business. This approach works well but has a limitation: MAPI can't generate referrals to a mailbox server that's in a different site or administrative group than the mailbox was originally in. That's one reason that Exchange versions earlier than Exchange 2003 SP1 restricted cross-administrative-group and intersite mailbox moves. Exchange 2003 SP1 fixes the other reasons, and ExProfRe takes care of this problem.

How does this new tool do the trick, you ask? ExProfRe updates the user's default profile to point to the new server. Specifically, it

- updates the name of the profile (which is actually an X.400-style distinguished name--DN) to point to the correct mailbox server, even if that server is in another site or administrative group;

- resets the offline address book (OAB) so that Outlook will download it from the new mailbox server;

- leaves the default profile's offline folders file (OST) alone when Microsoft Office Outlook 2003 is installed, but deletes and recreates the file when an earlier version of Outlook is present; and

- removes (or lets you rename) several objects that might no longer be valid after the move, including the user's favorites file and list of most-recently opened files.

ExProfRe does all this without any user intervention, or even much of a UI. The tool was designed to be run once for each user, so its command-line interface is oriented toward use in logon scripts or Group Policy Objects (GPOs). To run the tool, you must specify the target Global Catalog (GC) server, or you can use a variety of switches to control the changes the tool makes. You can use the /v and /r switches to turn on verbose logging and ExProfRe's read-only mode, respectively. Doing so lets you make a test run to see the changes that ExProfRe will make (without actually changing anything). You can find details about using ExProfRe in the Microsoft article "How to use the Exchange Profile Update tool" ( http://support.microsoft.com/?kbid=873214 ).

As the Exchange 2003 SP1 migration tools get more widespread use, ExProfRe will continue to be a key part of cross-administrative-group consolidations and migrations from Exchange Server 5.5. We'll see whether the tool evolves as customers provide feedback to Microsoft.