As you'll see, Exchange 2000 Service Pack 3 (SP3) contains numerous fixes and behavioral enhancements for Exchange 2000. Requirements Like most of Microsoft's service packs, Exchange 2000 SP3 is general purpose and cumulative. It does not require the installation of Exchange SP1 or SP2 since it incorporates all the fixes contained in those releases. Exchange 2000 SP3 does require the installation of Exchange 2000 on Windows 2000 Server. It also requires that Windows 2000 Service Pack 2 be installed. In addition, the release of Windows 2000 SP3 -- which closely coincided with the Exchange 2000 SP3 release -- is not only supported but highly recommended, as the combination of the two service packs increases security and reliability. In particular, the duo resolves a potential NDR problem related to an Exchange 2000 server querying a Global Catalog server that does not contain a complete copy of the Global Catalog (see Q304403). Individuals installing Exchange 2000 SP3 must now have Exchange Full Administrator rights for the administrative group of the server being upgraded. This is a change from previous Exchange service packs that required only Exchange Administrator rights. If you don't have these rights, you will be notified at the beginning of the installation. If you're running Microsoft Exchange 2000 Conferencing Server, this service pack is not for you. Microsoft will be releasing a separate rollup fix just for Exchange 2000 Conferencing Server. Installation tips The good news is that organisations running a multirole Windows server (one that runs services other than Exchange) will not necessarily have to reboot following the installation of Exchange SP3. I say necessarily, because it depends on the method of installation and what programs are running. Using Terminal Services to install Exchange 2000 SP3 will definitely require a restart. Third-party software like antivirus or e-mail filtering will likely have DLL files used by Exchange locked or open. To reduce your chance of requiring a reboot, these programs should be stopped if possible. The order in which you install Exchange 2000 service packs is the same as with previous service packs. Upgrade Exchange 2000 Active Directory Connector servers first, followed by front-end servers and then back-end servers. All bridgehead servers should have SP3 installed at relatively the same time to avoid bridgehead conflicts. Finally, upgrade systems are running just the Enterprise Systems Manager (ESM) so you don't lose management functionality. Servers running Exchange 2000 SP3 can fully coexist with servers running Exchange 5.5, Exchange 2000, Exchange 2000 SP1, and Exchange 2000 SP2. However, you can't use an Exchange 2000, Exchange 2000 SP1, or Exchange 2000 SP2 front-end server to access an Exchange 2000 SP3 back-end server. The setup program ensures that front-end servers are upgraded to SP3 before back-end mailbox servers. After installation, it is not possible to remove Exchange 2000 SP3. If you need to back out of the SP3 upgrade and revert to the original release of Exchange 2000, you must restore the original system state, file system, transaction log files, and databases. If you attempt to restore an SP2 database and log file set to an SP3 server, the database is automatically upgraded before it is mounted. However, if you attempt to restore a database that is older than Exchange 2000 SP2, the upgrade will fail. When you apply SP3 to a server, the databases are upgraded to a newer version. For this reason, you should immediately back up your server after applying SP3. You should also perform a test run of your Exchange 2000 deployment strategy on a test network. For large organisations with several Exchange servers, Microsoft's Exchange 2000 Deployment Guide is a must-read. This technical paper presents the best practices for deploying Microsoft Exchange 2000 Service Pack 3 and provides real-world tips for deployment. Author's note
If you want to verify that your Exchange 2000 server is running Service Pack 3, go to Exchange System Manager, click Servers, and check to see that the build stamp shows the server running build 6249.4.