When you configure an Outlook 2013 account to use Cached Exchange Mode, Outlook 2013 works from a local copy of a user's Microsoft Exchange mailbox that is stored in an offline data file (file) on the user's computer, together with the Offline Address Book (OAB).The cached mailbox and OAB are updated periodically from the Exchange Server computer.The email messages that are removed from the local cache are still available for users to view, but they’ll need to be connected to the Exchange Server computer to view them.
Summary: Learn about the two Exchange connectivity modes that you can use for Outlook 2013 deployments—Cached Exchange Mode and Online Mode.
Audience: IT Professionals Decide which connectivity mode, Cached Exchange Mode or Online Mode, is appropriate for your environment.
These operations won’t function when Outlook is not connected and can take longer to complete on high-latency connections.
These operations include: Delayed delivery options are client side in cached mode and server side in online mode.
Virtualized or Remote Desktop Services (RDS) (Terminal Services) environments that run Outlook 2013 and on which disk size or disk input/output (I/O) limitations prevent running Cached Exchange Mode at the scale you want.
If users work with a large mailbox, you can reduce the size of the local data file by using Cached Exchange Mode with the sync slider enabled.
So, when using Cached Exchange Mode, Outlook must be connected and open at the assigned delivery time for the delayed delivery message to be sent.
In Outlook 2013, Exchange Fast Access is a new feature that is available with Cached Exchange Mode.
If you’re an administrator, this article tells you about Cached Exchange Mode and Online Mode and helps you decide when to deploy each.