Microsoft has shelved a new security component for Exchange Server 2003. Instead, it will add its piece parts to a service pack and the next upgrade of the server.

Exchange Edge Services, first introduced in February 2004, is a message transfer agent (MTA) that can run at the edge of a network to provide customers with anti-spam, anti-virus and other messaging hygiene and policy-based features. Edge Services was intended to replace the current message transfer agent in Exchange, which has a dependency on Microsoft's Internet Information Server and Active Directory. The configuration can lead to open ports on the edge of networks that pose security risks.

Edge Services was to provide routing features and serve as a hub to plug in third-party e-mail security products from the likes of partners Network Associates, Sybari, Symantec and Trend Micro. It was also designed as a small cog in Microsoft's Dynamic Systems Initiative, a common management platform for Windows servers and desktops.

In May 2004, Microsoft said it would ship Edge Services in early 2005, but in November 2004, the company hinted that the date was in doubt. In late December, Microsoft confirmed that Edge Services would not ship as a separate product, and that some of its features would be integrated into Exchange 2003 Service Pack 2, due in the second half of this year, and the next release of Exchange. A ship date for the next version of Exchange has not been announced. Last year Microsoft removed the long-awaited Kodiak release from its road map.

Edge Services also featured support for the SenderID framework, a sender authentication mechanism that was on track for standardization but crumbled late last year within the Internet Engineering Task Force. Problems with SenderID, which is now being revised, may have had something to do with the delay of Edge Services, analysts say.

"If Microsoft could not release Edge Services with some sort of authentication system, then that would have [eliminated] one of the key reasons to buying Edge Services," says Peter Pawlak, an analyst with independent research firm Directions on Microsoft. "I think Microsoft realized that just crating competitive products to other [MTAs] wasn't going to sell any more licenses."