Exchange Server managed folders are used primarily to help control the size of users’ mailboxes. In the past, most Exchange organizations implemented mailbox quotas to manage mailbox sizes. However, the basic philosophy behind quota management is flawed.
Quotas are designed to prevent users’ mailboxes from growing too large; they force users to delete old messages in order to make room for new ones. But because quotas only look at the size of a mailbox, they don’t account for the fact that some messages are more important than others and should not be deleted. Users are often forced to delete everything, all in the name of staying within the confines of established mailbox quota.
Managed folders weren’t designed to replace mailbox quotas but they were meant to limit mailbox growth. More importantly, managed folders can help ensure that certain messages are retained for as long as is required either by law or by corporate policy.
If your organization is required to retain messages related to a specific project for five years, for example, you could create a custom managed folder and assign it with a five-year retention period. This folder will retain messages for the required length of time and then automatically purged them after that date.
Limiting mailbox data growth in Exchange 2010
Although storage costs continue to decline, storage management is more important in Exchange Server 2010 than it was in Exchange 2007. When Microsoft created Exchange 2010, it completely redesigned the database format to make it easier to access databases. In doing so, it did away with single instance storage (SIS); which was previously used to help limit mailbox database size.
Exchange Server 2010 does not use SIS, so when a user sends a message to 10 different recipients, Exchange stores 10 copies of that message in the mailbox database. This means that messages can consume more physical storage space than they did in previous versions of Exchange. Therefore, it’s important for Exchange 2010 administrators to limit database growth.
Suppose, for example, that your organization uses Exchange Server for email and Unified Messaging (UM). While a user is on her lunch break, she may receive an important project-related email. She may also receive a message informing her that she missed a phone call.
If there were no limits in place, the user might retain both messages indefinitely. Similarly, if mailbox quotas are the only way to control mailbox size, then the user may be forced to delete both messages, even though one of the messages is more important.
Managed folders give you greater control over in type of situation. A user can move more important messages to a designated folder where they can be retained for longer periods of time. The missed-call notification would remain in her inbox, which could be provisioned with a retention policy that deletes messages automatically after a week. This helps control the size of the mailbox without sacrificing important data.
Note: Don’t use managed folders instead of journaling or third-party archival products. You must have journaling or an archival system in place to ensure that copies of important messages are retained as required by law. Ultimately, it’s the end user’s responsibility to move messages into appropriate folders.
ABOUT THE AUTHOR
Brien M. Posey, MCSE, is a seven-time Microsoft MVP for his work with Windows 2000 Server, Exchange Server and IIS. He has served as CIO for a nationwide chain of hospitals and was once in charge of IT security for Fort Knox. For more information visit www.brienposey.com.