I have an old Outlook OST file that contains important emails, contacts, and attachments. Now, my organization has shifted to Zimbra Mail Server, which supports the TGZ format. Unfortunately, Outlook does not provide a direct option to export OST files into TGZ. Can anyone suggest a reliable way or tool to convert OST to TGZ without losing data? I would prefer a method that keeps my folder structure, attachments, and email formatting intact.