Applies to: Exchange Server 2007 SP3, Exchange Server 2007 SP2, Exchange Server 2007 SP1, Exchange Server 2007
Topic Last Modified: 2006-11-13

Message classifications are a Microsoft Exchange Server 2007 and Microsoft Office Outlook 2007 feature that is intended to help organizations comply with their e-mail policies and regulatory responsibilities. When a message is "classified," the message contains specific metadata that describes the intended use or audience of the message. Outlook 2007 or Microsoft Office Outlook Web Access may act on this metadata by displaying a user-friendly description of the classification to senders and receivers of a classified message. In Exchange 2007, the Microsoft Exchange Transport service may act on the metadata if there is a transport rule that meets specific criteria that are configured by the Exchange administrator.

The following list provides a brief description of some of the message classification fields that can be set by the Exchange administrator:

A good example of message classifications is the Attorney/Client Privilege (A/C Privileged) message classification. The A/C Privileged message classification is one of two default message classifications that are included with Exchange 2007. After Outlook 2007 is enabled to accept the default message classifications, users can apply the A/C Privileged message classification to messages that they send. Senders see the sender description in the InfoBar in Outlook 2007. By using the Exchange Management Shell, the Exchange administrator can customize the sender description for each message classification and locale.

Figure 1 shows how an Outlook user can apply the A/C Privileged message classification and the default sender description for the A/C Privileged message classification.

Selecting the Message Classification

As shown in Figure 1, the Outlook user opens a new message, and then on the Message tab, in the Options group, the user clicks Permission, and, from the Set Permission list, selects A/C Privileged.

When Outlook 2007 recipients receive messages that have the A/C Privileged message classification, they see the recipient description that explains the classification in the InfoBar as shown in Figure 2.

E-mail with Message Classification

For other types of message classifications, the recipient description may provide status information about the message in the recipient description. You can customize the recipient description for each message classification.

Outlook Web Access requires no special configuration to display or use message classifications.

In the initial installation of Exchange 2007, the A/C Privileged classification, and all message classifications, are informational only. They are not associated with rules. Default message classifications are a way for senders to communicate additional information about a message to the message recipients. In the A/C Privileged scenario, the classification describes the intended audience for the message and informs recipients that the message should only be forwarded by attorneys. By default, in Exchange 2007, the Microsoft Exchange Transport service does not take any special action on the A/C Privileged message.

However, the Exchange administrator can create a global transport rule that enforces the A/C Privileged classification. In the A/C Privileged scenario, if all attorneys in your organization are grouped into an organizational unit that is called "Legal", you can configure a transport rule that returns messages that are classified as A/C Privileged to the sender if the sender or at least one recipient on the To or Cc line is not in the Legal group. For a procedural example that shows how to enable this scenario, see How to Customize Default Message Classifications.

Message classifications can be logically separated into two classes based on how they are attached to a given message:

  • A message classification can be manually added by the sender of a message. This scenario is illustrated by the A/C Privileged example that is described earlier in this topic. In the A/C Privileged scenario, the users select a message classification before they send the message.

  • A message classification can be added as the result of a rule. For example, when the Attachment Filter agent removes an attachment from a message, the Attachment Removed message classification is attached to the message. The Attachment Removed message classification is a default classification. When the sender receives the message, Outlook 2007 displays an explanation of why the attachment was removed in the recipient description in the InfoBar. As the administrator, you can customize the recipient description. In this scenario, the message classification is added by a Transport agent.

You can associate transport rules behavior to message classifications to take advantage of forwarding rules, disclaimers, and other technologies that transport rules support.

Not all message classifications must be enforced or applied by a transport rule. In fact, an informational message classification is intended to notify the recipient of the sender's intention. Transport rules do not enforce informational classifications.

Regionalization and Localization

You can create more than one message classification instances for different languages. Therefore, in the A/C Privilege scenario, you can create a "localized" version of the A/C Privilege sender description and recipient descriptions for each language in your organization. If you have multiple, localized versions of a given message classification, Outlook and Outlook Web Access will display the correct version based on the language settings on the user mailbox. For more information, see How to Create Localized Versions of Message Classifications.

In some scenarios, your business needs may dictate following different regulations for different regions or locales where your business operates. In these cases, it may not make sense to display all message classifications to all users. For example, healthcare-related companies that operate in the United States and in Europe may have to comply with Health Insurance Portability and Accountability Act (HIPAA) regulations in the United States but not in Europe. Therefore, the display of message classifications that are HIPAA-specific should only be enabled for employees operating in the United States. You can set read permissions on classifications so that only appropriate users can view specific message classifications. For more information, see Managing Message Classifications.

Precedence and Retention of the Message Classification

By default, a message classification travels with a message for the life of the message until it leaves the organization. Therefore, if a sender sets the A/C Privileged message classification on a given message, the message will retain the message classification as long as other transport rules or higher precedent classifications do not remove it. Each message classification can be assigned a relative priority to other message classifications.

For example, you may set the precedence of the A/C Privileged message classification to Highest, and set the Attachment Removed message classification to Medium. If a user sends an A/C Privileged message that has a forbidden attachment to a member of the Legal group, the recipient will see the A/C Privileged recipient description, followed by the Attachment Removed recipient description. If the recipient forwards the message, only the A/C Privileged message classification travels with the forwarded message.

Therefore, setting precedence has two implications:

  • It specifies the ordering of the recipient descriptions.

  • It determines which message classification travels with a forwarded or replied message.

You set precedence by using the DisplayPrecedence parameter on the Set-MessageClassification cmdlet in the Exchange Management Shell.

For each message classification, you can specify whether the message classification is retained when a recipient replies to or forwards the message. You can specify whether a classification is retained by setting the RetainClassificationEnabled parameter on the Set-MessageClassification cmdlet in the Exchange Management Shell.

For more information, see Set-MessageClassification.

Managing and Deploying Message Classifications

Before Outlook 2007 users can set and view message classifications, you must deploy the message classification configuration files and create an Outlook registry key on the end-users' computers. The Outlook message classification templates are .xml files that you must generate after you have created and configured the message classifications.

You manage all message classifications by using the message classification cmdlets in the Exchange Management Shell. You can bind message classifications to transport rules by using the Exchange Management Shell or the Exchange Management Console.

For more information, see the following topics:

Figure 2   An inbound Outlook 2007 message that has the A/C Privileged message classification and default recipient description
Figure 1   An outbound Outlook 2007 message that has the A/C Privileged message classification and default sender description