In my first job in IT I was given an email address and a mailbox with a 20mb quota. Thats 20 megabytes. Unthinkable in today's business world, particularly when you consider Exchange Server 2010's default storage quotas of +2Gb and the Microsoft “large mailbox vision”.
The PST Nightmare
Naturally with such a small mailbox quota the entire organization made heavy use of PST files for storing email. When you had read an email and wanted to keep it, you moved it to the PST file immediately. Every week or so you would go to your Sent Items and move all your recent sent email into the PST as well. Deleted items were emptied automatically when Outlook closed.
Everyone had their own “system” for maintaining their email, but the results were basically the same – you stayed under your mailbox quota by creating a mess of PST files, and permanently deleting anything you didn't want to keep.
Of course these days PST files are a royal pain for everyone involved. The end users become frustrated when PST files are corrupted seemingly at random, or lost when they switch computers.
The IT administrators become frustrated with assisting end users with those problems, and the escalating cost of storing PST files on file servers.
And the business itself is often frustrated by information that is leaked or lost in PST files, unable to be discovered, searched, or secured.
Email Archiving Solutions
And so an entire industry segment evolved to deliver email archiving solutions to businesses, such as Symantec Enterprise Vault and GFI MailArchiver.
The benefits of these types of email archiving systems are obvious; the valuable information stored in email can be safely and centrally archived in a format that is secure, searchable, and also carries other benefits such as single-instancing, compression, and the ability to locate archives on different tiers of storage and with different backup/retention timelines applied.
Exchange Native Archiving
Unsurprisingly, Microsoft then delivered native email archiving capabilities in Exchange Server 2010. At RTM the feature was somewhat disappointing with a few desirable options missing, such as the ability to locate the archive mailbox for a user on a separate database to their primary mailbox.
However in Exchange Server 2010 SP1 that issue, and many others, were resolved and native archiving became an attractive option for organizations that were beginning to evaluate email archiving solutions.
Personal Archive Mailboxes
Exchange 2010 native archiving involves the provisioning of a personal archive, or archive mailbox, for end users. This is in effect just another mailbox, separate to their primary mailbox, stored in an Exchange mailbox database.
Archiving is enabled on a per-mailbox basis, and each user that is enabled for archiving requires an Enterprise Client Access License (CAL). This isn't enforced at the software level, it is your responsibility to ensure that you have the correct number of Enterprise CALs for the number of users you intend to enable for archiving.
- How to create an archive mailbox in Exchange Server 2010
- How to Find all Exchange Server 2010 Mailboxes with Archive Enabled
- Exchange 2010 Mailbox Can’t Be Archive-Enabled Due to Managed Folder Mailbox Policy
Thanks to the improvements in Exchange Server 2010 SP1 the archive mailbox for a user can be located on a different mailbox database to their primary mailbox. The mailbox database can be on the same mailbox server, or a different mailbox server, than the database that hosts the primary mailbox, as long as both servers are located within the same Active Directory site.
This allows you to locate mailbox databases that are dedicated to archive mailboxes on different servers, or on lower tiers of storage (although Exchange 2010 is already designed to run on low cost disk anyway), and apply different backup schedules and retention periods.
And because the archive mailbox database is otherwise the same as any other Exchange 2010 mailbox database, it can have the same high availability by being replicated within a Database Availability Group.
- How to Create an Archive Database in Exchange Server 2010
- How to Move an Archive Mailbox in Exchange Server 2010
Importing PST Files to Archive Mailboxes
For organizations that already have PST files on the network, one of the goals in the implementation of an email archiving solution may be to import those PST files into the archive so that they can be removed from the network for good. For Exchange Server 2010 native archiving there are two solutions available for this.
The first solution is to perform PST imports into the archive mailboxes. This has been available since Exchange Server 2010 SP1, however it requires that the IT administrators be able to locate the PST files and either manually run PowerShell commands or write a script to perform the import operations.
The second solution is to use the PST Capture Tool that Microsoft released in early 2012. This tool assists with the discovery and import of PST files on the network into either the primary or archive mailbox for Exchange 2010 and Office 365. Although a little more complicated to set up it does solve some of the issues associated with the previous manual approach.
- How to Import PST Files into Mailboxes with Exchange 2010 SP1
- Microsoft Exchange PST Capture Tool, and documentation
Archiving Email Automatically via Retention Policies
When a mailbox user has been enabled for archiving they are assigned a retention policy.
A retention policy is made up of a group of retention tags – at least one default tag, and then any number of additional policy tags or personal tags.
Although the tags that you are licensed to use in retention policies differ between the Standard and Enterprise CAL, since archiving is an Enterprise CAL feature anyway I will assume that you are entitled to the full range of retention tags.
There is already one default retention policy installed with Exchange Server 2010 so you should take a look at it first before you begin enabling mailboxes for archiving. The outcome of the default policy is that it will archive any items more than 2 years old, unless the mailbox user assigns one of the available personal tags instead.
Alternatively you can create your own retention tags and policies to suit your organization's archiving goals, such as this 30 day archive policy I've configured in my test environment.
You can add existing mailboxes to the new retention policy when you are creating it, or add them later.
Managed Folder Assistant
The Managed Folder Assistant is the agent that processes mailboxes and applies retention tags and performs actions on the mailbox items.
In Exchange 2010 RTM the Managed Folder Assistant operated on a schedule, however in Exchange 2010 SP1 this was changed to a “workcycles” approach instead, where the assistant runs and stops as necessary depending on the load the mailbox server is under at the time. This improves the reliability of the Managed Folder Assistant by increasing the likelihood that it will process all mailboxes in larger environments where a scheduled approach may not be suitable.
You can also manually run the Managed Folder Assistant from PowerShell.
Start-ManagedFolderAssistant -Identity alan.reid
The outcome is quite obvious. Here is the mailbox for Alan Reid prior to the Managed Folder Assistant running.
And here is the same mailbox after the Managed Folder Assistant has run.
As you can see from this brief overview, Exchange Server 2010 native archiving can be used to effectively manage the size of mailboxes by automatically moving items into personal archives.
However proper planning should always take place before implementing any email archiving solution. In the case of Exchange 2010 native archiving, considerations include:
- Is the organization licensed correctly for personal archives?
- Do the client computers have a compatible version of Outlook installed?
- Where will the archive databases be located, and will they be replicated within a Database Availability Group?
- How will the archive database be backed up?
- Which retention tags and policies will be assigned to mailboxes?