You can try commercial solution like KDETools Zimbra to Office 365 Converter Tool is the most powerful tool for migrating Zimbra to Office 365. Some additional features are:
Zimbra to Office 365 converter convert Zimbra TGZ file to Office 365 other file formats like PST, OLM, NSF, MBOX, PDF, EML, EMLX, HTML, etc.
This tool has Fast conversion of data without losing any data.
Corrupted file also transformed securely.
This tool works on all versions of Windows, including 7, 8, 8.1, XP, and 10.
