If you want to convert Zimbra to Office 365 then I suggest commercial solution like KDETools Zimbra to Office 365 Converter Tool is the most efficient tool for convert Zimbra to Office 365 and other popular file formats such as PST, MBOX, PDF, EML, EMLX, HTML, etc. This software support batch conversion at once. You can simply activate this tool in all versions of Windows such as 7, 8 and 8.1, XP, 10 and so on.
Read More: https://www.kdetools.com/zimbra/office-365.html