If you import Zimbra file to Office 365 account you can use any specialized tool like KDETools Zimbra to Office 365 Converter tool.
Advanced features like:
• Zimbra to Office 365 converter support various file formats such as PST, MBOX, MSG, EML, EMLX, PDF, OLM, HTML, etc.
• This tool easily import Zimbra file to Office 365 without losing data.
• This application also show preview item before completing scanning method.
Read More:
https://www.kdetools.com/zimbra/office-365.html
