I would like to suggest professional software like KDETools Zimbra to Exchange Server Converter.
• Zimbra to Exchange Server converter tool also directly convert Zimbra TGZ files to Gmail, G Suit, Google Drive and etc.
• Support multiple file formats such as PST, OLM, MBOX, MSG, EML, EMLX, PDF, HTML, etc.
• This tool also import Zimbra file to Office 365 mailbox and Exchange server this two format use for online Conversion.
Read More:
https://www.kdetools.com/zimbra/exchange/
