Timing is everything, whether you're ballroom dancing, skeet shooting, or deciding when to upgrade your Exchange Server environment. Many organizations that have resisted upgrading or migrating to Exchange Server 2003 are reconsidering now that mainstream support for Exchange 2000 Server and extended support for Exchange Server 5.5 have ended. But with the next version of Exchange, code-named Exchange 12, looming on the horizon, is migrating to Exchange 2003 Service Pack 2 (SP2) worth the time and effort? Let's consider your options.

Your Options, Pro and Con
Microsoft uses two terms to describe moving between different versions of Exchange. A migration is the process of moving from Exchange 5.5 to Exchange 2003 or Exchange 2000. An upgrade is the process of moving from Exchange 2000 to Exchange 2003, a fairly simple process. For this article I'm going to follow this usage instead of lumping the two terms together. The big difference between these two processes involves changes required to the underlying OS and directory architecture.

Organizations running Exchange 2000 or Exchange 5.5 have three options for moving to newer versions of Exchange, each of which has advantages and disadvantages. One option is to keep running whatever you've got until Exchange 12 ships (most likely sometime in the first half of 2007). You'll avoid spending money on new software for the interim; however, you'll have to have 64-bit hardware for Exchange 12—a requirement your current hardware probably can't meet—and your support options will be limited. (See the sidebar "Support Savvy" for an explanation of Microsoft support options.) If your environment is stable, these limitations might not worry you. But ask yourself what you'll do if Exchange stops working for some reason. For production email systems, having support available is always a good idea. You should carefully evaluate your organization's ability to deal with a serious problem without any support from Microsoft and your organization's willingness to pay for customized support services if necessary.

The second option is to move to Exchange 2003 now or very soon. If you do so, you'll be moving to a supported, stable platform that still has several more years of mainstream support, and you won't have to wait for Exchange 12 to ship. Although moving now might disrupt your existing environment, particularly if you haven't moved to Active Directory (AD), the disruption could also give you an opportunity to make changes to your environment to reflect the best practices now used for Exchange and AD design. These practices have changed significantly in the 6 years since the introduction of Exchange 2000. Bear in mind that this will buy you time, but eventually even Exchange 2003 will hit the end of the product lifecycle, and you'll be facing the same decision.

The third option, which is beyond the scope of this discussion, is to move to another messaging system. Although some companies find that switching to another system gives them more functionality than their current Exchange implementation, no other messaging platform offers features and benefits equivalent to those of Exchange 2003, particularly when you consider the integration between Outlook, Exchange,-Microsoft SharePoint Portal Server, and Microsoft Office Live Communications Server 2003.

One thing you should consider, which I didn't include in the previous calculations, is the role of the Microsoft Software Assurance (SA) program. The idea behind SA is simple: When you buy a product with SA, your license costs are spread across a 3-year period. If new versions of the products you've bought are released during that 3-year window, you get them for free. This can be a good deal in some cases, less so in others.

However, now that Microsoft has articulated a range of planned ship dates for Exchange 12, anyone who buys SA for Exchange 2003 now will get Exchange 12 when it ships. The same is probably also true for the next release of Windows Server, code-named Longhorn Server, if you buy Windows Server 2003 to support your new Exchange implementation.

Migrating from Exchange 5.5
I'm always surprised to hear of uncertainty and complaint surrounding migration from Exchange 5.5 to a newer version, given that Exchange administrators have had to deal with the associated challenges of migration for almost 6 full years. The process of moving mail and directory data from Exchange 5.5 to Exchange 2000 or Exchange 2003 is well understood by now. Microsoft offers a ton of guidance about the process; third parties such as Quest Software make migration tools that greatly ease the burden of the actual migration; and in-the-trenches articles, blog entries, and other helpful resources abound. Having said all that, organizations that are still using Exchange 5.5 probably believe they have good reasons for choosing not to migrate.

Cost is one reason why organizations resist migrating. Spending money to upgrade something that's already working is hard to justify. However, "working" in this context is a bit of a misnomer. The scalability, security, and functionality improvements between Exchange 5.5 and Exchange 2003 are many. For example, being able to recover data to a Recovery Storage Group (RSG), instead of needing a recovery server, is worth the upgrade cost for many organizations, as are the integrated support for wireless access to email and the vastly improved Microsoft Outlook Web Access (OWA) interface. What's more, server consolidation, when properly planned and executed, can drive down the cost of your messaging operations. A 2004 report by Ferris Research (available from http://www.microsoft.com/exchange/evaluation/MigrateLowCost .mspx) pegs the migration cost for moving from Exchange 5.5 to Exchange 2003 at less than $200 per mailbox.

Unfamiliarity with AD is another reason why some avoid migration. True, moving from Exchange 5.5 running on Windows NT 4.0 systems can be complicated, particularly for organizations that haven't used AD.

However, NT passed into the netherworld on January 1, 2005, and most organizations have already done the groundwork to move to AD. Those that haven't are putting their organization's security at risk because Microsoft no longer makes NT security updates broadly available (unless, of course, you've purchased a custom support agreement). In its security documentation, Microsoft vigorously warns against using NT in production networks.

Yet another reason for stalling on migration is the "if it isn't broken, why replace it" argument. Nonprofit organizations, small government agencies, and schools often find that Exchange 5.5 is good enough for what they want to do, so justifying the expense of migrating, given that many new features in Exchange 2003 will probably remain unused, can be difficult. However, such organizations need to realize that the benefits of security and stability are as important in their situations as in enterprise scenarios. There's enough documentation and guidance from Microsoft to make the cost of learning how to do the migration, and how to manage the new environment, minimal. It's true, software licenses drive up costs, and you might have to factor in training expenses for users who are upgrading to new versions of Outlook. However, if you put these costs into context by comparing the potential savings from server and site consolidation to the outlays required for the migration, you'll find that migration comes out ahead.

The migration process requires several steps. I won't go into great detail here, but it might be helpful to check out the articles listed in the Need to Know More? box. Microsoft also has a wealth of documentation (see http://www.microsoft.com/technet/prodtechnol/exchange/2003/up grade.mspx) that explains these steps.

First, if you haven't already installed and set up Active Directory Connector (ADC), you'll need to so that ADC can copy your Exchange 5.5 directory data to AD. Organizations that are running Exchange 5.5 on Windows 2000 have probably already taken this step. (For more information about ADC, see "Get Inside Active Directory Connector Synchronization," February 2006, InstantDoc ID 48589 and "Fine-Tune Active Directory Connector Synchronization," March 2006, InstantDoc ID 49022.)

Second, you need to create a plan for hardware upgrades. Exchange 5.5 hardware requirements are modest by current standards, but many sites that are still using Exchange 5.5 have needed to upgrade their hardware since the release of Exchange 5.5 (especially given that hardware vendors have continued to drive down the price of high-availability features such as hot-swappable disks and redundant power supplies). If you're still running Exchange 5.5 on your original servers, you'll probably need to replace them; this would be a great time to ensure that the servers you buy are 64-bit capable so you can easily move to Exchange 12 when it ships.

Third, you have to upgrade Exchange software on the servers. Microsoft doesn't support in-place upgrades from Exchange 5.5 to Exchange 2003. You can upgrade your Exchange 5.5 servers to Exchange 2000 and then to Exchange 2003, or you can just install a new Exchange 2003 machine and move the Exchange 5.5 mailboxes to it. This latter approach is simpler, safer, and faster.

Fourth, and sometimes most troublesome, is that most messaging environments have lots of additional "stuff" that has to be upgraded and maintained. You'll need to replace any antivirus scanners, fax gateways, or other add-ons that run on your Exchange 5.5 servers. In some cases, you might find that some older products are unavailable in a version that works with Exchange 2003; in those cases, you'll need to either keep a 5.5 site around to keep running those products or find other similar products that do what you need.

This sounds like a lot of work, and it can be. However, in support of migration, by moving to Exchange 2003, you can cut the number of email servers required. If so, you might end up saving money on your upgrade. Individual circumstances will vary, but many companies see the number of deployed servers drop by 30 to 50 percent or more when Exchange 2003 is deployed. This is compelling evidence in support of migrating, given that reducing server count is perhaps the fastest way to reduce the cost of messaging operations (for any system, not just Exchange!).

Upgrading from Exchange 2000
Upgrading from Exchange 2000 to Exchange 2003 is much simpler than migrating from Exchange 5.5.You know that AD is already set up and working; not having to set up AD or learn how it operates tends to raise administrators' comfort levels. Also, Microsoft supports in-place upgrades from Exchange 2000 to Exchange 2003. Of course, just because Microsoft supports something doesn't mean that you should use it; there are arguments both for and against in-place upgrades. (See "A Religious Debate: Upgrade in Place vs. Reinstall," September 2005, InstantDoc ID 47614.) One compromise is to set up a new Exchange 2003 computer and use it to hold mailboxes as you upgrade. Suppose you have four Exchange 2000 servers: A, B, C, and D. You set up a new server, which I'll call E, and move mailboxes from A and B to E. You can then safely upgrade A and B to Exchange 2003, move the mailboxes back from E, and repeat the process with C and D.

Of course, a more likely outcome is that you move the mailboxes from A and B and leave them on E, decommissioning A or B (or both, and consolidating their workload onto a single server). The same site-and server-consolidation arguments that apply to Exchange 5.5 migrations also apply to Exchange 2000 upgrades. Exchange 2003 also offers scalability improvements beyond Exchange 2000. In the past, Microsoft has offered trade-up programs for organizations that buy the current version of a server product before the next version ships; they may or may not do this again for Exchange 12. Even if they don't, the increased security and capability of Exchange 2003 make it a worthwhile upgrade for shops using Exchange 2000 now.

Don't Wait for Exchange 12
By now, it should be pretty clear that the best solution for most organizations is to upgrade, or migrate, to Exchange 2003 now, rather than wait for Exchange 12. By doing so, you get many immediate benefits, including improved security, easier management, better stability, and a variety of features (including wireless and mobile access and support for Outlook 2003's Remote Procedure Call over HTTP—RPC over HTTP) that will make your messaging environment more stable, less expensive to operate, and more pleasant for both administrators and users.


If you want more information about migrating and upgrading, take a look at these articles, available online at http://www.windowsitpro.com/microsoftexchangeoutlook. (Accessing some articles might require registration, a print subscription, or a monthly pass.)

Migrating Exchange 5.5 to Exchange 2000, InstantDoc ID 39533

Migrating from Exchange 5.5 to Exchange 2003, InstantDoc ID 39791

Troubleshooter: Migrating an Exchange 5.5 Environment to a Pristine Win2K AD/Exchange 2000 Environment, InstantDoc ID 37541

Exchange Server 2003 Migration Made Simple, InstantDoc ID 40454

Troubleshooter: Upgrading an Exchange 5.5 Cluster, InstantDoc ID 43613

Fine-Tune Your Exchange 5.5 Migrations, InstantDoc ID 43274