ost file) on the user's computer, together with an Offline Address Book (OAB).Ĭached Exchange Mode's purpose is to provide a seamless online and offline Outlook experience. When an Exchange account in Outlook is configured to use Cached Exchange Mode, Outlook works from a local copy of the user's Exchange mailbox that is stored in an offline data file (. Outlook for Mac desktop versions (including 2016) support only Cached Exchange Mode.Ĭached Exchange Mode is the default and recommended configuration for most scenarios except those mentioned under When to use Online Mode.
