Microsoft KB Archive/925474

= Information about the types of anti-spam updates that are available for Exchange 2007 =

Article ID: 925474

Article Last Modified on 11/27/2007

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APPLIES TO


 * Microsoft Exchange Server 2007 Enterprise Edition
 * Microsoft Exchange Server 2007 Standard Edition

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INTRODUCTION
This article describes the types of anti-spam updates that are available for Microsoft Exchange Server 2007.



MORE INFORMATION
Microsoft delivers anti-spam updates for the spam filter in Exchange 2007 through Microsoft Update. The spam filter in Exchange 2007 must be regularly updated to counter the quickly changing tactics of those who send spam. These updates are important to maintain the effectiveness of the anti-spam capabilities of Exchange 2007. The following spam filter updates are available for Exchange 2007, depending on the Client Access License (CAL) options that you selected.

Exchange 2007 Standard CAL

 * Anti-spam definition updates

These updates enable the Exchange 2007 content filter to distinguish between legitimate e-mail and spam based on a variety of message characteristics. Because malicious senders change these characteristics frequently, the content filter must be updated regularly to provide continued spam protection. Spam definition updates are delivered every two weeks. The updates must be downloaded from the Microsoft Update Web site to the Exchange 2007 server.

Exchange 2007 Enterprise CAL and Forefront Security for Exchange Server

 * Anti-spam definition updates

These updates enable the Exchange 2007 content filter to distinguish between legitimate e-mail and spam based on a variety of message characteristics. Because malicious senders change these characteristics frequently, the content filter must be updated regularly to provide continued spam protection. Spam definition updates are delivered automatically by Microsoft Update to the Exchange 2007 server one time each day.
 * Spam signature updates

Spam signatures are another set of characteristics that are derived from the content of e-mail messages. These characteristics can help distinguish legitimate e-mail from spam. Signatures are used by the content filter to help identify spam campaigns that consist of similar types of e-mail messages. Spam signature updates are delivered automatically by Microsoft Update to the Exchange 2007 server several times each day.
 * IP reputation updates

By analyzing the pattern of e-mail messages that are sent from a given IP address, Microsoft can build a reputation for that IP address. IP reputation updates contain the latest information about IP addresses that have been identified as sources of spam. This reputation information is used by the Exchange 2007 Sender Reputation functionality to help make spam filtering decisions. IP reputation updates are delivered automatically by Microsoft Update to the Exchange 2007 server several times each day.

You must configure Exchange 2007 to automatically receive these updates from Microsoft Update. For more information about how to configure Exchange 2007 for automatic updates, visit the following Microsoft Web site:

http://technet.microsoft.com/en-us/library/42cd5fe3-15f9-44eb-8dc2-c30a247a6686.aspx

