Apply Exchange Server 2010 message retention tags for email archiving

Federal regulations require companies to retain email messages for a specified period of time. Microsoft Exchange Server 2010 makes message retention easier with some built-in features. In this introductory tip, you'll learn about Exchange Server 2010 retention tags and retention actions.

For several years, various federal regulations and other legal issues have forced organizations to retain and archive email messages for a specified length of time. But how these messages were retained was difficult to administer without of the use of third-party software.

In Exchange Server 2007, users have to manually move messages to specific managed folders that are set with a desired retention policy. The use of retention tags in Exchange Server 2010 facilitates message retention.

What is a retention tag?

A retention tag is used to control how long certain items are retained for and what happens to them when the retention period expires. Retention tags can be applied to individual items or entire folders. A collection of retention tags is called a retention policy. You can assign one retention policy per mailbox.

Exchange Server 2010 supports the use of a few different types of retention tags:

  • Retention policy tags -- These tags are applied to default folders -- mailbox folders that are created in Outlook by default such as Inbox, Junk Mail, or Sent Items.

    When a retention policy tag is applied to a default folder, items within the folder automatically inherit the tag. Users can apply a different retention tag to individual items within a default folder, but not to the folder itself.

    Although most of the default folders support the use of retention policy tags, a few do not. These include the Calendar, Contacts, Journal, Notes and Tasks folders.

  • Default policy tags -- Think of this tag as catch-all retention tag. A default policy tag applies to any item that is not explicitly assigned a retention tag or that does not inherit a retention tag from a folder.

  • Personal tags -- End users can manually apply retention settings to custom folders or to individual items within a folder using a personal tag. These tags are often used to specify a retention setting other than the default folder setting.
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New unified messaging features in Exchange Server 2010

New high availability features in Exchange Server 2010

What is a retention action?

All retention tags include a retention action, which tells Exchange Server what to do with messages once they reach a specified retention age. Exchange Server 2010 includes the following retention actions:

  • Mark as past retention limit -- Until you get a solid handle on message retention, I suggest using this retention action. The mark as past retention limit action displays messages in a strikethrough font (on supported versions of Outlook only) to indicate that the message has expired. Therefore, expired messages aren't automatically deleted. Once you confirm that message retention is working correctly, you can use a different retention action.
  • Move to archive -- In Exchange Server 2010, every user has two mailboxes: a primary mailbox and an archive mailbox. The move to archive action moves expired messages into a user's archive mailbox.
  • Permanently delete -- This action deletes messages in order to prevent users from recovering them. Messages are only recoverable if they are a part of a legal hold. These messages are inaccessible to end users, but a multi-mailbox search will reveal the deleted messages.
  • Delete and allow recovery -- When this action is used, expired items are moved to the Recoverable Items folder, where they can be recovered if necessary.
  • Move to the Deleted Items folder -- This action transfers expired items to the user's Deleted Items folder, just as if a user had deleted them manually. It makes it easy for users to retrieve expired messages if necessary.

About the author: Brien M. Posey, MCSE, is a five-time recipient of Microsoft's Most Valuable Professional (MVP) award for his work with Exchange Server, Windows Server, Internet Information Services (IIS), and File Systems and Storage. Brien has served as CIO for a nationwide chain of hospitals and was once responsible for the Department of Information Management at Fort Knox. As a freelance technical writer, Brien has written for Microsoft, TechTarget, CNET, ZDNet, MSD2D, Relevant Technologies and other technology companies. You can visit Brien's personal website at

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