This problem occurs because the Cached Exchange Mode Sync Slider setting is configured to a value other than All. For example, the following figure shows a profile configured with Cached Exchange Mode and with the Sync Slider set to the default value of 12 months.
Please use the following steps to modify the number of months of email to synchronize with your cached mode .ost file:
- Start Outlook.
- Click Account Settings on the File tab, and then click Account Settings.
- In the Account Settings dialog box, double-click your Microsoft Exchange account on the E-mail tab.
- In the Change Account dialog box, drag the Mail to keep offline: slider to the desired number of months.
- lick Next.
- Click OK when advised you have to restart Outlook to complete the configuration change.
- Click Finish.
- Restart Outlook