Exchange 2007 includes several improvements to the suite of anti-spam and antivirus features that were introduced in Exchange Server 2003. These improvements, provided by the Exchange 2007 Edge Transport server role, include the following:

• Improved content, connection, and recipient filtering.
  
• Sender Reputation, which can be based on either the domain name or IP address.
  
• Administrative quarantine features.
  

Exchange 2007 offers anti-spam features that can detect spam messages regardless of the languages that the spam e-mail messages are written in. The anti-spam engine relies on a content filtering agent, which is the next generation Exchange Intelligent Message Filter. The Intelligent Message Filter is based on patented machine-learning technology from Microsoft Research. Intelligent Message Filter evaluates inbound e-mail messages and assesses the probability that an inbound message is legitimate or spam. Unlike many other filtering technologies, Intelligent Message Filter uses characteristics from a statistically significant sample of e-mail messages. The inclusion of legitimate messages in this sample reduces the chance of mistakes.

Note:
Updates to Intelligent Message Filter are available periodically through Microsoft Windows Update.

Microsoft Forefront Security for Exchange Server helps protect your e-mail infrastructure from infection and downtime through an approach that emphasizes layered defenses, optimization of Exchange Server performance and availability, and simplified management control. Forefront Security for Exchange Server is an on-premise solution that provides protection for Exchange 2007 Edge and Hub Transport server roles.

• Advanced Protection   Forefront Security for Exchange Server provides multiple scan engines at multiple layers throughout the e-mail and collaboration infrastructure to provide maximum threat protection.
  
• Improved Availability and Performance   Forefront Security for Exchange Server includes scanning innovations, performance controls and tight integration with Microsoft Exchange Server to improve the overall availability and performance of messaging environments.
  
• Simplified Management   Forefront Security for Exchange Server helps ensure organizations can simply and cost-effectively manage the security of their messaging servers.
  

The client antivirus protection that is provided by Forefront Security for Exchange Server is language independent. However, the setup, administration of the product, and end-user notifications are available in 11 server languages. When Forefront Security for Exchange Server detects messages that seem to contain a virus, the system generates a notification message and sends the notification to the recipient’s mailbox. However, the notification message is written in the language of the server that is running Forefront Security for Exchange Server because that server does not detect the language of the destination mailbox.

For more information about Forefront Security for Exchange Server, see Protecting Your Microsoft Exchange Organization with Microsoft Forefront Security for Exchange Server.

Spam filtering is enhanced by or is also available as a service from Microsoft Exchange Hosted Services. Exchange Hosted Services is a set of four distinct hosted services:

• Hosted Filtering, which helps organizations protect themselves from e-mail-borne malware
  
• Hosted Archive, which helps them satisfy retention requirements for compliance
  
• Hosted Encryption, which helps them encrypt data to preserve confidentiality
  
• Hosted Continuity, which helps them preserve access to e-mail during and after emergency situations
  

These services integrate with any on-premise Exchange servers that are managed in-house or Hosted Exchange e-mail services that are offered through service providers. For more information about Exchange Hosted Services, see Microsoft Exchange Hosted Services.

For more information about the Edge Transport server role, see Edge Transport Server Role: Overview.

For more information about antivirus and anti-spam features, see New Anti-Spam and Antivirus Functionality.