Applies to: Exchange Server 2010 SP3, Exchange Server 2010 SP2

Topic Last Modified: 2010-01-22

Organizations and users handle an increasing volume of e-mail every day. The growing volumes of e-mail contain messages that are important to the organization from a business, legal, or regulatory perspective, and may need to be retained for a certain period, depending on the organization's messaging policies. However, many e-mail messages may not have any retention value beyond a certain period, if at all. For example, a user's mailbox may contain critical messages that need to be retained, such as messages related to business strategy, transactions, product development, or customer interactions. However, messages such as newsletter subscriptions or personal e-mail may not have any retention value, and therefore don't need to be retained beyond a certain period. Retaining messages with little retention value results in mailbox growth that requires more resources on mailbox servers.

Messaging records management (MRM) is the records management technology in Microsoft Exchange Server 2010 that helps organizations reduce the legal risks associated with e-mail. MRM makes it easier to keep the messages needed to comply with company policy, government regulations, or legal needs, and to remove content that has no legal or business value. This is accomplished through the use of retention policies or managed folders:

When a message reaches its retention age, the retention action specified in the retention tag (or the managed content settings for a managed folder) is taken. Messages can be moved to the Deleted Items folder, deleted with the ability to recover them from the Recoverable Items folder, or permanently deleted. Retention tags also provide an additional action of moving a message to the user's archive mailbox, if an archive mailbox has been provisioned for the user. Managed content settings for managed folders also provide an additional action of moving a message to a managed custom folder.

Messaging Records Management Strategy

Retention policies and managed folders provide two different approaches to MRM. You can use either MRM technology to enforce basic MRM policies on default folders and on the entire mailbox. For MRM to be effective, users must participate in the process of classifying messages based on their nature and retention value.

With retention tags, you can apply default retention settings to default folders such as the Inbox folder, and apply a default policy tag (DPT) to the entire mailbox. The DPT retention settings are applied to untagged items that may reside in folders without a retention tag, such as custom folders created by the user. Retention tags help both types of users: Users who file e-mail into folders and keep few messages in the Inbox, and users who leave most of their e-mail in the Inbox. Retention tags have a lesser impact on the user's workflow because users aren't required to file messages in folders based on the folder's retention settings. They can apply any personal tag to custom folders, and also explicitly apply a different tag to individual messages.

With managed folders, users participate in the MRM process by classifying their own messages and sorting them into managed folders. This sorting process ensures that messages are classified according to the users' preferences and the organization's needs. It also helps eliminate the mishandling of messages that can occur with a completely automated messaging management solution.

The strategy to make Exchange 2010 messaging retention management and policy enforcement more reliable, effective, and easy to use is based on three principles:

  • Users classify their own messages.

  • Messages that have no retention value are removed.

  • Messages that have some retention value are retained.

Users Classify Their Own Messages

With Exchange 2010, users participate in the MRM process by classifying their own messages. Users with a retention policy applied can either move a message to a folder that has a retention tag applied or can apply a personal tag to the message. If the user doesn't take any action, one of the following retention settings is applied:

  • Messages in default folders with a retention policy tag applied   If the message is located in a default folder that has a retention policy tag applied, the folder's retention settings are applied to the message.

  • Messages in custom folders with a personal tag applied   If the message is located in a custom folder to which the user has applied a personal tag, the folder's retention settings are applied to the message.

  • Messages in default or custom folders without a retention tag   If the message is located in a default or custom folder that doesn't have a retention tag applied to it, the DPT is applied to the message.

Regardless of the location of the message, any time a user explicitly applies a tag to a message, the user's action is honored.

Messages That Have No Retention Value Are Removed

Retention policies and managed folder mailbox policies are applied to the user's mailbox by the Managed Folder Assistant. This assistant processes mailboxes that have a retention policy or a managed folder mailbox policy applied. For mailboxes that have a retention policy applied, the Managed Folder Assistant applies the retention tags included in the policy to default folders and the entire mailbox. Any personal tags included in the policy are provisioned and become available to users in Microsoft Outlook 2010 and Microsoft Office Outlook Web App.

Messages That Have Some Retention Value Are Retained

Messages that have some retention value are retained based on the retention settings applied to the message, folder, or mailbox. However, keep in mind that users can delete or remove messages from their mailbox; MRM isn't designed to prevent users from deleting their own messages. If your organization requires messages to be retained outside a user's mailbox for long-term storage, consider implementing journaling. To learn more about journaling, see Understanding Journaling.

If your organization wants to preserve messages for users to meet e-discovery and retention requirements, consider deploying large mailboxes and placing those users on legal hold. To learn more about legal hold, see Understanding Litigation Hold.