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Deciding Whether to use Cached Exchange Mode

We have plenty of bandwidth for our Outlook users. Should we bother deploying Microsoft Office Outlook 2003 in Cached Exchange Mode ?

For some reason, many administrators think that the chief benefit of running Outlook 2003 in Cached Exchange Mode is the reduction in bandwidth usage. This reduction occurs because Exchange Server 2003 and Outlook 2003 together implement several optimizations for Messaging API (MAPI) traffic; these optimizations are described in more detail at However, you get this benefit whether you use Outlook 2003 in online mode, offline mode, or Cached Exchange Mode. The best thing about Cached Exchange Mode is really that it greatly reduces users' perception of bandwidth shortages or general network interruptions; for example, working with a locally cached copy of the calendar is more pleasant than calendaring over a slow or flaky network line. The bandwidth savings that come from deploying Exchange 2003 with Outlook 2003 (in any mode) can be significant, but the improvements in user productivity and satisfaction that cached Exchange mode offers are often what make that mode worthwhile.

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