While conducting whiteboard sessions at MEC last week a number of people wanted to talk about the Sync Slider in Outlook 2013. Specifically, what is it, when do I use it, and how does it fit into the Exchange Personal Archive story? First, a quick look at just what we're talking about. In Outlook 2013 the default profile configuration is to have Cached Mode enabled. But there's a new slider that appears in the account settings that allows you, the user, to limit the amount of email that is synchronized locally to the OST cache. The default setting is 12 months (which we'll come back to in a moment).
Let's first look at this from a pure Outlook perspective. A few years ago the average mailbox size was relatively low – 200-300mb or even smaller and 1GB was the exception. These days the average is in the low GB range with 5, 25, 50 or even 100GB mailboxes being a reality. Combine this with the number of computers that people have that are running Outlook and you can see we may run into network or resource bottlenecks. Now, I'm not the average email user, but I have an 8GB mailbox with 5 different computers running different versions of Outlook. Each time I add a machine or rebuild my Outlook profile, I have to download all of that data from the Exchange server. Apply this to a large enterprise and you can see how this can place a burden on the network.
Now let's briefly review the Exchange 2010 Personal Archive. By default when a user's mailbox is provisioned with an Exchange Personal Archive, messages that are older than 24 months are moved from the Primary Mailbox to the Personal Archive. In Outlook 2010 and older running in Cached Mode this meant that only the Primary Mailbox (or the past 24 months) of email was synchronized to the Outlook OST cache file. The main premise behind this is that the majority of the time users only access their most recent email. The exception is to open the messages that are 3, 6, 12+ months old. So when the Personal Archive was introduced it gave us a pretty good way to give users a very large mailbox without having to deal with the challenges around large OST files.
Enter the Outlook 2013 Sync Slider and we now have another tool in our chest to help manage large mailboxes. As I mentioned the default setting for the Sync Slider is 12 months and can be set via GPO. Once a message is older than 12 months Outlook will remove it from the OST cache. Now what about those messages that are older than 12 months? Well, when you scroll to the end of a folder list you can select the option: "Click here to view more on Microsoft Exchange". I should also point out that the Sync Slider only applies to email – Calendar, Contacts, Tasks, Journal, and Notes are always synced.
This will probably create some confusion and helpdesk calls as Outlook 2013 is deployed and tested. Microsoft has already posted a KB article: "Only a subset of your Exchange mailbox items are synchronized in Outlook 2013" most likely to deal with questions/problem calls from users running the Technical Preview. For the Enterprise I see this as a great way to manage large mailboxes but also empower users to manage how much email they want to have cached locally. For folks like myself who have a number of machines running Outlook and syncing data, I'll probably have my primary machine sync all mail out of my primary mailbox, then other machines sync 1-3 months. Check out Office 2013 here.