Exchange Server 5.5 Service Pack 3 (SP3) made it out the door at Microsoft last week, so I thought I would drill into more about what's in the update. First, as most service packs do, Exchange Server 5.5 SP3 includes a roll-up of all the fixes since SP2. These fixes are Quick-Fix Engineering (QFE) patches, and a listing of these QFEs should be available via Product Support Services (PSS) in the next week as Microsoft Support Online article Q235452 (http://support.microsoft.com/support/kb/ articles/q235/4/52.asp). The SP3 distribution files include more details.

SP3 includes Windows 2000 (Win2K) Release Candidate 1 (RC1) support for Exchange Server 5.5. Because many customers will first migrate to Win2K, Exchange Server 5.5 support is a must-have feature. In my estimation, most customers won't want to migrate to both Win2K and the Exchange Server Platinum release simultaneously. Running Exchange Server 5.5 on Win2K will be the natural baby step.

SP3 puts significant focus on additional migration and interoperability features. Microsoft added many enhancements to the various connectors for competing and legacy messaging systems, such as GroupWise, PROFS/SNADS, and Lotus Notes/Domino. For Lotus messaging, Microsoft added several enhancements to support Domino Release 5 (R5) and improve interoperability with Exchange Server and enable successful migration.

With SP3, Microsoft enhanced MBClean, which is now Exchange Server Mailbox Manager (EMM). You can use EMM to enforce organizational email retention policies by regularly deleting messages that match the rules you specify. Some features of EMM include automated and scheduled operations, folder-level granularity, deletion by message size, user notification, administrative reporting, and greater administrative control. This tool went out to several customers last May in beta form and is a welcomed addition to any Exchange Server administrator's toolbox.

Last, but not least, is the Store-based Virus Checker API. For Microsoft PSS, concern about Exchange Server antivirus products from various third parties always seem to top the charts. Easing this pain called for a common method for these tools to access the Exchange Server information store (IS). Microsoft implemented the interface at a very low level in the IS, taking into account things such as single instancing of both messages and attachments. This approach will allow a virus-scanning implementation with high performance, but at lower risk to reliability (because it's integrated with Exchange Server). Microsoft will provide only the virus-scanning interface, and third parties that specialize in virus-scanning products will implement the interface. Although not an earth-shattering release, SP3 has some features that are worth the wait.