Microsoft issued a bit of good news, bad news last week when it revealed that its previously expected Microsoft Exchange Server Edge Services product wouldn't ship in 2005 as planned. Instead, Microsoft will roll the features from Exchange Edge Services into the next service pack for Exchange Server 2003 and into the next major version of Exchange, code-named Kodiak.

So what was Exchange Edge Services (sometimes referred to as Exchange Server Edge Services)? Originally a set of technologies designed for email protection, enhanced security, and junk email management, Exchange Edge Services would have expanded the roles that an Exchange server could perform. Those new roles would have included a more secure and reliable SMTP gateway for exchanging (ahem) email with the Internet, a basic infrastructure for antispam (based on the Caller ID for Email protocol) and antivirus technologies that Microsoft's partners could have built on, and a new routing-rules engine that would have let administrators more easily build custom rules for relay, masquerading, and the like. Microsoft designed Exchange Edge Services to be installed directly on an Exchange server box or on different systems on your network, with the idea that these services would logically sit between the core Exchange functionality and the outside world.

Microsoft introduced Exchange Edge Services in February 2004 at the RSA Conference 2004 in San Francisco. The product was to ship in early 2005. Microsoft had never announced its licensing plans for the product, but my guess is that the company would have provided the product to existing customers for free. The product also changed over time, with Microsoft adding support for messaging policy and antiphishing functionality at the request of customers.

That's all changed. Under the new plan, some technology from Exchange Edge Services will now appear in Exchange 2003 Service Pack 2 (SP2), currently due in the second half of 2005. These technologies include an improved version of Exchange Intelligent Message Filter (IMF) and new antispam technologies that are based on the Sender ID framework, rather than on Caller ID for Email. Sender ID is a proposed email authentication standard that Microsoft hopes will be adopted by a wide range of ISPs. Microsoft resubmitted Sender ID to the Internet Engineering Task Force (IETF) for possible standards ratification in October 2004 after making some compromises based on feedback it received from partners and critics such as AOL. "Basically all the antispam functionally originally planned for \[Exchange\] Edge Services will be delivered in Exchange 2003 SP2, including updates to the Intelligent Message Filter and antiphishing technology," a Microsoft spokesperson said last week.

Most Exchange Edge Services technologies, however, will ship as part of the next major version of Exchange Server, which is tentatively slated to ship in 2007 alongside Longhorn Server. Those technologies include the new messaging policy functionality and the routing-rules engine. Microsoft says the delay is caused by two needs. First, most Exchange customers are still migrating to Exchange 2003. Second, feedback indicated that customers were looking for a more extensive set of functionality, and delivering that functionality will require additional time. So the company has decided to break out the features originally slated for Exchange Edge Services over two releases, Exchange 2003 SP2 and the next major version of Exchange.

So what should existing Exchange 2003 customers do? Microsoft notes that IMF technology is available to all Exchange 2003 customers and that IMF has been extended by third-party providers for those users who need additional functionality. This is a "making lemonade" solution, of course. Arguably, this type of functionality should be included in the base product (a notion that Microsoft implicitly agrees with, based on its product plans).

If you're still running older versions of Exchange, your options are less compelling, particularly for Exchange Server 5.5 holdouts. As the Exchange team has noted repeatedly this year, Exchange 5.5 was developed when the world was a very different place. Exchange 5.5, like Windows NT 4.0, is now reaching a crucial juncture in its support life cycle. As of January 1, 2005, Exchange 5.5 enters its final year of extended support, and Microsoft will no longer support the product unless you purchase a custom support license (available in 3-month increments through the end of 2007). The idea, naturally, is to give customers time to migrate to Exchange 2003. You can find out more about this schedule on the Microsoft Web site. http://www.microsoft.com/exchange/evaluation/previous/55.mspx