Executive Summary:

Upgrade to Outlook 2007 and then migrate legacy mailboxes from Exchange Server 2003 to Exchange Server 2007 using the new Move Mailbox wizard.


As you learned in part 1 of this series, “Upgrading to Exchange Server 2007,” August 2007, Instant- Doc ID 96240, preparing your existing Exchange Server 2003 organization for an upgrade to Exchange Server 2007 is a multistep process, which includes installing Exchange 2007 onto a new server, then migrating the data from the legacy servers that your Exchange 2007 server will replace. Here, I’ll continue explaining the Exchange 2007 migration steps by showing you how using a new wizard can streamline the migration process. But before you start moving mailboxes, I recommend that you back up your data, choose an email client for your users, and let your users know that they could experience delays in accessing a Web email client to get their Exchange email during the migration process.

First Things First: Backing Up Your Data
Before you move data from your Exchange 2003 servers to your new Exchange 2007 server, I strongly recommend that you make a full backup of all of your Exchange servers and Active Directory (AD). Although I haven’t heard reports of any catastrophic problems during a migration, having a full backup of all of your Exchange servers and AD is a good precautionary measure.

Upgrading to Outlook 2007
Although you don’t have to use Microsoft Office Outlook 2007 if your organization is running Exchange 2007, I strongly recommend that you upgrade to Outlook 2007 before moving any mailboxes to your

Exchange 2007 server.
Exchange 2007 has a number of new features, such as the Scheduling Assistant and Instant Search, that users can’t take advantage of unless they’re running Outlook 2007. See the Learning Path for more on the new features in Exchange and Outlook.

Using OWA
In addition to thinking about upgrading to Outlook 2007, it’s equally important to consider that some users might access their mailboxes through Microsoft Outlook Web Access (OWA). When you move a user’s mailbox to a different server, the user can still access the mailbox through OWA without any configuration changes. The catch is that the first time users sign on to OWA after the move has occurred, they’ll likely experience a long delay between the time they log on and the time they can start accessing email. Therefore, you’ll need to warn OWA users in advance about this delay and tell them that it’s a one-time occurrence.

In my experience, the delay typically lasts for a minute or so, but in some situations it could last for several minutes and even give the appearance that the user’s Web browser locked up. According to Microsoft, the longest delays occur when Exchange is processing mailboxes containing 1GB or more of data in which the user has sorted messages using a field other than the default, which is the date the messages were received.

Exchange is designed to automatically create a view of each user’s messages sorted by the date the messages were received. Exchange can create alternate tables for other message views, but these tables aren’t created until a user actually attempts to use a view that requires them. So when someone who uses an alternate view to sort mail logs on to OWA for the first time after his or her mailbox has been moved, the alternate view won’t exist yet. The delay occurs while Exchange builds the table for the user’s chosen view. The larger the user’s mailbox, the longer this process takes, thus the longer the delay that the user experiences.

As I’ve said, this delay should happen only once. Assuming that the user gives Exchange the chance to perform all necessary tasks, the next time the user logs on to OWA, OWA should respond normally.

Moving User Mailboxes
The actual technique for moving mailboxes to an Exchange 2007 server is simple. You start by opening Exchange Management Console. Then, in the console tree at the left, under Recipient Configuration, click Mailbox. The result pane displays a list of all mailboxes in the Exchange organization, as Figure 1 shows.

Notice the Recipient Type Details column in Figure 1. Some recipients are listed as having a Legacy Mailbox, while one recipient has a User Mailbox. Legacy mailboxes exist on Microsoft Exchange 2000 Server or Exchange 2003 servers. User mailboxes exist on Exchange 2007 servers.

I’m calling out these distinctions because I want to emphasize the differences between Exchange 2003 and Exchange 2007 mailboxes. Exchange 2007 mailboxes contain attributes that simply don’t exist in Exchange 2003. Because of this, you can’t use the Microsoft Management Console (MMC) Active Directory Users and Computers snap-in to move a mailbox from an Exchange 2000 or Exchange 2003 server to an Exchange 2007 server. Instead, you need to use Exchange Management Console to do so.

Launching the Move Mailbox Wizard
To start your organization’s mailbox migration, open Exchange Management Console, rightclick the mailbox you want to move, and select the Move Mailbox command from the shortcut menu. Exchange will launch the Move Mailbox wizard, as Figure 2 shows.

The Move Mailbox wizard can also perform bulk mailbox moves. To move multiple mailboxes, in the console select all the mailboxes you want to move, click the right mouse button, and choose the Move Mailbox command from the shortcut menu. As you can see in Figure 2, you can specify a mailbox’s destination by selecting the server, storage group, and mailbox database to which you want to move the mailbox.

Click Next, and you’ll see a prompt asking what you want to do if Exchange encounters corrupt messages during the move. By default, the Move Mailbox wizard skips the mailbox containing the corrupt messages. However, you can opt to copy the mailbox but not the corrupt messages. As Figure 3 shows, the wizard also lets you choose to specify a maximum number of corrupted messages to skip within each mailbox.

Using Move Schedule
Click Next, and the wizard’s Move Schedule screen opens. As you can see in Figure 4, you have the option of scheduling the mailbox move to occur at a specific time. By default, the Move Mailbox wizard will move the mailboxes you’ve selected immediately upon completion of the mailbox migration via the wizard. If you’re moving only a few mailboxes, the default will probably be fine for you. If you’re moving a lot of mailboxes, you’ll want to use the scheduling feature.

You can use Move Schedule to schedule the mailbox move to occur late at night when the servers involved in the move are likely to be carrying a minimal workload. Doing so is not only an efficient way to use your servers, but it also lets you move users’ mailboxes after hours when they’re typically not in use. If you’ve scheduled the mailbox move using Move Schedule, you don’t have to come back to the office late at night to start and babysit the operation. (However, I recommend testing the Move Mailbox feature on a few mailboxes before you do a large-scale move of many mailboxes, just to make sure that you won’t have any unanticipated problems.)

You can choose an option in Move Schedule that lets the wizard cancel a task that’s been running too long, depending on the number of hours you’ve specified for this option. I recommend using this option, because I’ve seen situations in which a mailbox had problems, but the mailbox wasn’t recognized by the wizard as being corrupt and caused the wizard to hang during the move. Setting the wizard to abort a move after a given number of hours lets you avoid the server handing should this type of problem occur. If you decide to set an abort threshold in Move Schedule, make sure the time period is long enough to cover moving your largest mailbox, so that you don’t cancel a task unnecessarily.

Reviewing Move-Mailbox Options
When you finish scheduling the move, click Next, and you’ll see a screen that displays a summary of the move options you’ve chosen, as Figure 5 shows. Review the options, and click the Move button to move the selected mailboxes. If you’ve scheduled a move to occur at a later time, clicking Move gives the move permission to occur, but the wizard will not launch the move until the scheduled time.

When the move is completed, click the Finish button to close the wizard. When you go back to the Exchange Management Console, Recipient Configuration, Mailbox node, you’ll see the mailboxes that you’ve moved are now listed as User Mailboxes.

After the Migration
After your migration to Exchange 2007 is done, I recommend keeping your Exchange 2003 servers online for a couple of weeks. Although performance problems or compatibility issues are rare, I’ve seen posts on various Web sites from administrators who’ve encountered such problems after migrating to Exchange 2007. If your Exchange 2003 servers are online, you’ll be able to temporarily move mailboxes or public folders back to them should you encounter unexpected problems. (You can use the Exchange 2007 Move Mailbox wizard to move mailboxes from an Exchange 2007 server back to a legacy Exchange server.)

Even when you’re confident enough in your Exchange 2007 server that you’re ready to retire your Exchange 2003 servers, I recommend leaving at least one Exchange 2003 server online until you can take advantage of the features Microsoft provides in Exchange 2007 SP1. This service pack adds features to Exchange Management Console, such as public folder–management capabilities, that weren’t included in the original release of Exchange 2007. However, since the final release of SP1 isn’t scheduled until after Windows Server 2008 is released, if you want to manage public folders and perform certain other administrative tasks via a GUI administrative console, you’ll need to do so by using Exchange System Manager (ESM) on your Exchange 2003 server, until Exchange 2007 SP1 is available. (However, if you want to perform public folder– management tasks via the command line, you can do so now by using Windows PowerShell cmdlets in Exchange Management Shell.)