You can try professional tool like KDETools Zimbra to Gmail Converter. This tool has many advanced features:
• Zimbra Converter to convert Zimbra file to Gmail and other different file format such as PST, MBOX, EML, EMLX, PDF, NSF, OLM, and many more.
• This application also directly migrate Zimbra file to Exchange Server and Office 365 account.
• This software shows a free preview of the data before the migration process.
Read More:
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