1. Open Microsoft Outlook on your computer.
2. Click on the "File" tab in the top-left corner of the window.
3. In the File menu, click on "Account Settings," and then choose "Account Settings" from the drop-down menu.

4. In the Account Settings window, select the email account for which you want to enable cached mode.
5. Click the "Change" button located above the list of email accounts.
6. In the Change Account window, check the box next to "Use Cached Exchange Mode."

7. You can customize the amount of data that Outlook should download for offline use by clicking the "More Settings" button. In the Offline Settings window, adjust the slider to set the desired amount of time or choose "All" to download all data.
8. Click "OK" to close the Offline Settings window.
9. Click "Next" and then "Finish" to complete the setup process.
10. Outlook will prompt you to restart the application to apply the changes. Close Outlook and reopen it for the changes to take effect.