Cached Exchange Mode can provide you with a better experience when you use Outlook. A copy of your mailbox and GAL (Global Address List) is cached on your computer. This copy provides quick access to your data and is frequently updated with the mail server. Note: the time required to complete the initial synchronization will depend on the size of your mailbox. Access to all data is not available until the initial synchronization is complete.


Most users will find that Cached Exchange Mode performs faster than online mode.   Use of Cached Exchange Mode shields the user from network and server connection issues and facilitates switching from online to offline for mobile users.

Enabling Cached Exchange Mode


Cached Exchange Mode is enabled by default when you configure an Microsoft 365 account and is also highly recommended. If you have Cached Exchange Mode disabled for some reason, you can enable it by following the steps below:

  1. Choose File | Account Settings | Account Settings
  2. Double click on your email account.
  3. Select the box for Use Cached Exchange Mode. The default setting is 12 months - change this to your preference.
  4. Click Next.
  5. Click Finish.
  6. Close Outlook and then restart it.

To disable Cached Exchange Mode, repeat the steps but uncheck "Use Cached Exchange Mode".


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Last updated: 
September 19, 2023