Using Exmerge
The Exmerge utility helps fill the gaps in Exchange 2000's and Exchange Server 5.5's built-in mailbox-moving functionality. You can use Exmerge to move Exchange Server 5.5 mailboxes between servers in different sites. You can also use Exmerge to move Exchange 2000 and Exchange Server 5.5 mailboxes between Exchange Server organizations. Although Exmerge can also be a key migration tool, the topic of migrating an Exchange Server 5.5 system to Exchange 2000 is too complicated and lengthy to pair with this discussion of mailbox and same-version server moves.
You can find the latest release of the multipurpose Exmerge utility in the Exchange 2000 CD-ROM's \support\utils\i386\exmerge folder. This version of the utility runs only on Windows 2000 machines but works with both Exchange 2000 and Exchange Server 5.5 mailboxes. This release sports several useful enhancements—not the least of which is the ability to process multiple mailbox moves simultaneously—that make chasing Exmerge down worth the effort. If you don't have an Exchange 2000 CD-ROM handy, you can probably sweet-talk a copy of Exmerge out of Microsoft Product Support Services (PSS).
To move a group of mailboxes between organizations, use Exmerge in batch mode, as Microsoft recommends. You can feed Exmerge a list of the DNs of the mailboxes you want to move, and the utility processes the moves simultaneously. However, before you run Exmerge, you need to create the mailboxes on the target server to ensure that target DNs exist. The utility exports each old mailbox's email to a personal store (PST), then reimports the email to the new mailbox you've created. You can perform such an export and import procedure manually, but the process would be tedious for one mailbox, let alone hundreds or thousands.
Exchange Server 5.5 and earlier provide recipient containers, which are containers that you can create to hold mailboxes and custom recipients. (AD's organizational units—OUs—are the rough equivalents of Exchange Server 5.5's recipient containers.) Administrators often create recipient containers to group users by location, department, or other seemingly convenient criteria (this practice isn't one I recommend; you can use other methods to achieve the same grouping effect). Recipient container objects take their container names as part of their DNs, which complicates moving these objects between containers. Only Exmerge can rewrite an individual recipient's DN and let you move this recipient to another container on a different server. However, Exmerge can't move recipients between containers on the same server.
Exmerge has a few additional limitations for mailbox moves. Exmerge doesn't guarantee that its moves will preserve any data other than messages, so don't expect all your rules to relocate. This rule-relocation problem arises because Exchange Server rules use folder IDs rather than folder names. When you move a mailbox, the folder IDs often change. Make sure you warn your users about this limitation before you move their mailboxes. Also, running Exmerge can take quite a bit of time, so if you need to move a lot of mailboxes from one server, consider moving the server instead of the mailboxes.
Moving Servers
How easily you can move a server depends on the Exchange Server versions your systems run, the server's location (i.e., its group, site, or organization), the location to which you're moving the server, and your Exchange Server organization's design. Moving Exchange 2000 machines between administrative groups is probably the least complicated scenario—but only because you shouldn't make such a move at all. If you decide to disregard this advice and use Win2K's ADSI Edit tool to make a move manually, don't go crying to PSS if you break something: Microsoft officially doesn't support Exchange 2000 moves between administrative groups. To move Exchange 2000 systems between routing groups, simply use Exchange System Manager (ESM) and drag systems between the groups.
If you run only Exchange Server 5.5, you can use the Move Server Wizard (MSW) to move servers between organizations or sites within an organization. To move a server, the MSW needs to modify the DN of every object related to or homed on that server. Before you run MSW, make sure you've read and understood its documentation and release notes. I also recommend that you read Tony Redmond, "How to Rebuild Your Exchange Organization," January 1999.
MSW doesn't move Exchange 2000 systems between organizations. In fact, Exchange 2000's only use for MSW is to move Exchange 5.5 systems into a mixed-mode organization. Microsoft purportedly is developing better server-moving tools for Exchange 2000.
Moving On Up
The need to move mailboxes or Exchange Server systems is inevitable. After all, nothing is permanent: Even the procedures for moving Exchange Server objects change. However, inevitable changes won't always be annoyances. Although each new Exchange Server product version revises object-moving procedures, these changes can improve object-moving capabilities to let you easily move what once was immovable.
End of Article
Tariq Azad May 18, 2004