Between end users treating their Inboxes as de facto filing cabinets, and federal regulators that specify lengthy e-mail retention times, administrators trying to keep their Exchange servers slim have their work cut out for them.
A easy way to trim down Exchange data stores is for end users to use Microsoft Outlook's AutoArchive function, which archives old messages to a so-called Personal Store File (PST). This approach is used by "virtually everyone," says Andrew Barnes, European marketing director for KVS, which makes Enterprise Vault, an e-mail archiving tool for Microsoft Exchange.
But PSTs are highly flawed. For one thing, they can get easily corrupted. And if they get too large, Outlook may not be able to open them.
In terms of how they use storage space, PSTs are equally bad. For one thing, once messages are out of Exchange's purview, you lose the benefits of a single image store (SIS), whereby objects such as attachments are only written once. As a result, messages stored in PSTs actually take up more space than they do within Exchange. And because PSTs usually reside on the end user's hard drive, they are less likely to get backed up.
Not surprisingly, vendors such as KVS and Legato--with its EmailXtender family of products--recommend archiving as a way to lessen the Exchange load. Originally developed to help companies with records retention, Legato's Reier says that some customers are looking at EmailXtender "because Exchange has created such a storage management nightmare."
Market predictions from research firm The Radicati Group bear out Reier's analysis. In 2001, the market for e-mail active archiving stood at $58 million. By 2006, the market is expected to swell to $573 million, with a compound annual growth rate of 77%.