In Microsoft Office Outlook 2007 or 2010, your Outlook profile is configured to use a Personal Folders (.pst) file (also known as an Outlook Data File) as the default email delivery location, and your Outlook profile also includes an Exchange account that is configured to use Cached Exchange Mode. In this configuration, you may experience one or more of the following issues:
You receive duplicate copies of incoming email messages.
You cannot accept meeting invitations. When you open a meeting request, you see the following warning in the information bar:
This meeting is not in calendar; it may have been moved or deleted.
When you try to respond to a meeting invitation or cancellation by clicking Accept, Tentative, or Cancel, you receive the following error message:
Cannot open the calendar folder for user_name. Your profile is not configured to support this operation for this user.
Note In this message, the placeholder user_name represents your account name.
Because of these limitations, we do not recommend the configuration that is described in the "Symptoms" section. To prevent unexpected issues, we recommend that an Exchange account always be set as the delivery location. By default, if the Exchange account is configured to use Cached Exchange Mode, the delivery location is the offline folder (.ost) file (also known as the offline Outlook data file).
To set your default email delivery location back to the OST file in Outlook 2010 and Outlook 2007, follow these steps.
Click File, Account Settings, and then Account Settings.
On the E-mail tab, click Change Folder.
Click Yes on the warning message.
Select the OST file, click OK.
Click the Data Files tab.
Select the OST file, click Set As Default.
TIP You can expand the Location column to view the whole path and determine which item is the correct OST file.
Exit Outlook and start it again for the changes to take effect.
Click Tools, Account Settings.
Click the Data Files tab.
Select the OST file and click Set as Default.
Click OK on the warning message.
Quit Outlook and restart it for the changes to take effect.
Additionally, we recommend that you enable Cached Exchange Mode for the primary Exchange account in your Outlook profile and that you set Outlook to deliver email messages to the .ost file. There are many advantages to delivering email messages to the .ost file. These include, but are not limited to, the following:
You can work offline and synchronize changes when you reconnect to your Exchange server.
You can choose folders to synchronize and to keep current.
You can centrally store email messages on the Exchange server to let multiple clients and Outlook Web Access or Outlook Web App (OWA) access the mail.
In some circumstances, email messages that are delivered to a local .pst file may not be retained on the Exchange server. This may be a factor if email messages must be retained for legal or disaster-recovery purposes.
In Microsoft Outlook 2013, the ability to deliver email to an Outlook Data File (.pst) when a Cached Mode Exchange Account is also added to Outlook, is discontinued. If you have an Outlook profile configured in this manner in an earlier version of Outlook, upon upgrading to Outlook2013, profiles that are configured to delivery Exchange Server account items to an OutlookData File (.pst) continue to see the file in the Navigation Pane. However, all new items are delivered to an offline OutlookData File (.ost) and Cached Exchange Mode is turned on for the Exchange account.