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    Outlook.com comes with OneDrive: free online storage for your files and photos. Learn more about what you can do with Outlook.com and OneDrive.
    When you synchronize your Exchange mailbox to an Offline Folder file (.ost), the Outlook status bar never shows higher than 3.99 GB when a folder is being updated. For example, you may see the following text in the status bar when your Inbox folder is...
    Explains how to configure the size limit for both .pst and .ost files in Outlook. The article lists four registry entries that you can use to limit the size of both the .pst and the .ost files.
    Provides a description of the 4 GB RAM Tuning feature and the Physical Address Extension parameter.
    Microsoft Office Outlook 2007 and Microsoft Office Outlook 2003 have both a different format and a larger overall size limit for the personal folders (.pst) file than the .pst files that are in the earlier versions of Microsoft Outlook. In Outlook 2002...
    Explains that the handle count for the COM+ Event System process may grow and eventually exhaust the virtual memory. Provides a method to resolve this problem.
    Fixes an issue in which COM+ server applications on a Windows Server 2003-based computer experience intermittent crashes when the /3GB parameter is enabled.
    Describes the issue where you may not be able to add more data to the .pst file or the .ost file if the offline files or the personal folder files are bigger than 2 gigabytes (GB).
    Describes an issue in which the file size limits of .pst and .ost files are larger in Outlook 2010 and Outlook 2013.

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