c#读取web应用程序上的pst文件和提取.msg文件

using Microsoft.Office.Interop.Outlook;

public void ExtractMsgFromPst(string pstFilePath, string outputFolder)
{
    Application outlookApp = new Application();
    NameSpace outlookNamespace = outlookApp.GetNamespace("MAPI");
    MAPIFolder pstFolder = outlookNamespace.OpenStore(pstFilePath).GetRootFolder();

    foreach (object item in pstFolder.Items)
    {
        if (item is MailItem mailItem)
        {
            mailItem.SaveAs(Path.Combine(outputFolder, mailItem.Subject + ".msg"));
        }
    }

    outlookNamespace.Logoff();
    Marshal.ReleaseComObject(outlookNamespace);
    Marshal.ReleaseComObject(outlookApp);
}