The upcoming release of Microsoft Exchange Server 2010 includes new email archiving features.  Previously the domain of third party add-on products from various software vendors, this marks the first time it has been built in to the Exchange Server product itself.

Given the long and proven history of some of the third party solutions one wonders whether Microsoft’s first attempt at a built in archiving feature will compare favorably.  Let’s take a look at what we know so far about archiving in Exchange Server 2010.

Exchange Server 2010 Archiving

There are a few pre-requisites for Exchange Server 2010 archiving to function.  Firstly, it requires Enterprise CALs for the users that will be archive enabled.  In addition, the archive mailbox is only viewable using Outlook 2010 (due for release sometime after Exchange 2010), which means Outlook 2007 and prior versions will not be able to see it, although it is visible using the Exchange 2010 Outlook Web App.

The archiving feature can be enabled on a per-mailbox basis.  Once enabled it creates a second mailbox for the user, the archive mailbox.  Mailbox items can be moved to the archive mailbox either manually or via the use of Retention Policies set by the administrator.

Unlike the primary mailbox, the archive mailbox cannot be cached by Outlook for offline access.  This reduces the file size of the cached OST file on the end user’s computer; however, this benefit is somewhat redundant because the OST file format in Outlook 2007 SP2 and Outlook 2010 has been greatly optimized and will now run quite efficiently at large sizes such as 10 gigabytes.Although the archive mailbox is a separate mailbox it is still contained within the same mailbox database as the user’s primary mailbox.

Comparison to Third Party Archiving Products

I’m going to compare Exchange 2010 archiving to third party products in general terms rather than specifically compare different products feature by feature.  Even in general terms some of the points are quite valid and may give pause to customers considering deploying Exchange 2010’s archiving feature.

Firstly the Enterprise CAL requirement means additional costs.  For a smaller organization hoping to utilize a built-in archiving feature for Exchange this additional cost can be more than the licenses for a third party product.  Unless the organization is also planning to use other features that the Enterprise CAL provides it may be wiser to choose another product.

The decentralized model of archive mailboxes is also a potential concern.  Third party archiving products offer the capability to draw all archives into a central location where they are more manageable.  Exchange 2010’s model keeps archives distributed around all of the branches of an organization where the mailbox servers are located.

The limitation of placing the archive mailbox in the same mailbox database is also somewhat disappointing.  Archives by their nature are less frequently accessed and are perfect for low cost storage.  Unfortunately with Exchange 2010 the archive mailboxes can’t be placed in a different database on slower, cheaper disk.  That said, Exchange 2010 has dramatically improved its disk performance which may mean the databases are already stored on lower cost disk.  This will vary depending on the scale of the organization.

It is also unclear as to whether the archive mailboxes are simply included with the regular Exchange mailbox backups, or if they can be separated out and backed up less often.  Again an advantage of third party products is that once items are archived they don’t necessarily need to be backed up nightly within the archiving product.

Retention and discoverability are two areas where Exchange 2010 seems to get it right.  Archives are searchable by non-IT staff (e.g. HR, Legal) via an easy to use control panel, and items of interest can be copied elsewhere for further analysis.  Furthermore, a “legal hold” can be placed on individual mailboxes or an entire organization to prevent any item deletion by end users.

Summary

Exchange Server 2010 is due for release within a few weeks and until then the full archiving feature cannot be properly assessed and understood.  However based on current information it may not be the inexpensive built-in solution they are hoping for.